Dissertations / Theses: 'Rotenona'

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Araujo, Stífani Machado. "Efeito protetor do γ-orizanol em um modelo de doença de parkinson induzida por rotenona em Drosophila melanogaster." Universidade Federal do Pampa, 2016. http://dspace.unipampa.edu.br:8080/xmlui/handle/riu/313.

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Doença de Parkinson (DP) é a segunda doença neurodegenerativa mais comum no mundo, afetando cerca de 1% dos adultos com mais de 60 anos. A DP está relacionada com a degeneração de neurônios dopaminérgicos principais componentes da substância negra cerebral, concomitantemente, com a disfunção do complexo I mitocondrial e o estresse oxidativo que desempenham um papel crucial na patogênese desta doença. A rotenona (ROT) é um pesticida natural e muito utilizado para induzir fenótipo de DP em modelos animais, por ser lipofílico pode atravessar facilmente a barreira hematoencefálica causando disfunção do complexo I mitocondrial e possível morte de neurônios dopaminérgicos. Dentre as várias aplicações terapêuticas dos antioxidantes, ressalta-se sua ação neuroprotetora, uma vez que o sistema nervoso central exibe uma maior vulnerabilidade e susceptibilidade aos insultos oxidativos, o γ-orizanol (ORY) é um produto natural composto por uma mistura de ésteres de ácido ferúlico extraídos a partir do óleo de farelo de arroz, e é bem descrito na literatura por possuir propriedades antioxidantes. Assim, o objetivo deste trabalho foi investigar um possível efeito neuroprotetor do γ-orizanol sobre alterações comportamentais e bioquímicas causadas pela exposição crônica de Drosophila melanogaster a rotenona. A mosca da fruta Drosophila melanogaster, é uma espécie alternativa à utilização de modelos mamíferos que vem sendo usada com bastante confiabilidade na reprodução de modelos de disfunção dopaminérgica. As moscas (de ambos os sexos) com idades compreendidas entre 1 a 5 dias de idade foram divididos em quatro grupos de 50 moscas cada um: (1) de controle, (2) ORY 25 μM, (3) ROT 500 μM, (4) ORY 25 μM + ROT 500 μM. As moscas foram concomitantemente expostos a uma dieta contendo ROT e ORY durante 7 dias de acordo com os seus respectivos grupos. Após o tratamento foram feitas as analises comportamentais e bioquimicas. Como resultados, verificamos que o ORY ofereceu proteção contra as alterações locomotoras causadas por ROT, além de prevenir a mortalidade induzida por rotenona, protegeu contra geração de estresse oxidativo e disfunções mitocondriais além de otimizar as defesas antioxidantes celulares. Nossas descobertas apontam uma restauração dos déficits colinérgicos, e nos níveis de dopamina fornecida por pelo tratamento com ORY. Em conclusão, os presentes resultados mostram que ORY é eficaz na redução da toxicidade induzida ROT em Drosophila melanogaster, o que mostrou uma ação neuroprotetora, possivelmente devido à presença dos componentes de antioxidantes tais como o ácido ferúlico.
Parkinson's disease (PD) is the second most common neurodegenerative disease in the world, affecting about 1% of adults over 60 years. The DP is linked to the degeneration of dopaminergic neurons main components of the substantia nigra brain, concurrently with mitochondrial complex I dysfunction and oxidative stress play a crucial role in the pathogenesis of this disease. The rotenone (ROT) is a natural pesticide, and used to induce PD phenotype in animal models, being lipophilic can easily cross the blood-brain barrier dysfunction causing mitochondrial complex I and possible death of dopaminergic neurons. Among the various therapeutic applications of antioxidants, it emphasizes its neuroprotective action, as the central nervous system displays a greater vulnerability and susceptibility to oxidative insults, the γ-oryzanol (ORY) is a natural product composed of a mixture of esters ferulic acid derived from rice bran oil, and is well described in the literature to possess antioxidant properties. The objective of this study was to investigate a possible neuroprotective effect of ORY on behavioral and biochemical changes caused by chronic exposure of Drosophila melanogaster the rotenone. The fly fruit Drosophila melanogaster, is an alternative species to the use of mammalian models that have been used quite reliable reproduction of dopaminergic dysfunction models. The flies (male and female) between the ages of 1 to 5 days of age were divided into four groups of 50 flies each: (1) control, (2) ORY 25 μM, (3) ROT 500 μM ( 4) ORY 25 μM + ROT 500 μM. The flies were simultaneously exposed to a diet containing ROT and ORY for 7 days according to their respective groups. After treatment were made behavioral and biochemical analysis. As a result, we find that the ORY offered protection against locomotor changes caused by ROT, and to prevent the mortality induced by rotenone, protected against the generation of oxidative stress and mitochondrial dysfunction and optimize cellular antioxidant defenses. Our findings point to a restoration of cholinergic deficits, and dopamine levels provided by the treatment ORY. In conclusion, the present results show that ORY is effective in reducing the ROT induced toxicity in Drosophila melanogaster, which showed a neuroprotective effect, possibly due to the presence of antioxidants components such as ferulic acid.

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Villar, Maria Luiza Domingues. "Conteudo endogeno de rotenona e pachyrhizina em Pachyrhizus tuberosus (Lam.) Spreng." [s.n.], 1991. http://repositorio.unicamp.br/jspui/handle/REPOSIP/315160.

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Orientador : Ivany Ferraz Marques Valio
Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Biologia
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Resumo: Pachvrhizus tuberosus é uma espécie que possui um potencial alimentar expressivo nas raízes tuberosas. É nativa da região Amazônica, onde é cultivada comercialmente. Suas sementes são ricas em proteínas e lipídeos, porém são tóxicas ao consumo dos animais, pois apresentam um alto nível de isoflavonóides, rotenona e pachyrhizina. Entretanto, com exceção das sementes, nenhum trabalho foi desenvolvido para verificar a presença desses componentes nos vários órgãos da planta. Sendo assim, o objetivo deste trabalho foi determinar, através das extrações e dosagens, a quantidade de rotenona e pachyrhizina, na fase de crescimento inicial e nos vários órgãos da planta. Além disso, verificou-se também o efeito dessas substâncias na atividade respiratória em mitocôndrias isoladas desta espécie. Neste trabalho foi possível estabelecer o método por cromatografia líquida de fase reversa para determinar e identificar a rotenona e pachyrhizina de P. tuberosus. A partir da fração de rotenóides extraídos das sementes de P. tuberosus, foi possível identificar e determinar a rotenona e pachyrhizina no mesmo cromatograma. Observou-se que a rotenona elue em 13 minutos e a pachyrhizina em 11 minutos aproximadamente, utilizando ácido acético 0.5% e metanol 70%, numa velocidade de fluxo de 1ml por minuto. Após várias análises feitas por HPLC, observou-se que as sementes secas possuem cerca de 0.59mg de rotenona e 20.mg de pachyrhizina por miligrama de matéria seca. Durante o período de embebição em luz e escuro, verificou-se que rotenona e pachyrhizina estão em maior quantidade nos cotilédones do que nos eixos embrionários. Parece não ocorrer síntese dessas substâncias nos embriões e cotilédones, durante a embebição dessas sementes , pois, de acordo com os resultados, não houve variações significativas na quantidade dessas substâncias. Não existe uma relação entre o aumento do peso de matéria seca, com a quantidade de rotenona e pachyrhizina encontrada durante a embebição das sementes. É proposto que os níveis dessas substâncias, não interfiram no desenvolvimento das plântulas desta espécie. Rotenona e pachyrhizina foram encontradas também em sementes fervidas, com alta temperatura e pressão. Neste trabalho, foi possível estabelecer os níveis de rotenona e pachyrhizina nas folhas de P. tuberosus, utilizando a cromatografia líquida de fase reversa. Nas folhas primárias analisadas, observou-se um aumento na quantidade de pachyrhizina e principalmente de rotenona, concomitante com o aumento de matéria seca. Essas substâncias se apresentam em maior quantidade nas folhas primárias do que nas sementes em desenvolvimento. Não foram detectadas, rotenona e pachyrhizina no exsudato do caule e no pedúnculo da inflorescência nesta espécie. Além disso, nenhum desses isoflavonóides foi encontrado na inflorescência de P. tuberosus. E sugerido que rotenona e pachyrhizina não sejam transportadas no caule, indicando que possam ser sintetizadas independentemente nos diferentes órgãos (sementes, folhas e raízes).Nos frutos, rotenona e pachyrhizina não foram determinadas nos extratos das vagens e sementes imaturas. Estes isoflavonóides só foram detectados nas sementes das vagens com 15.8cm, 18.4cm e 20.9cm de comprimento. Rotenona e pachyrhizina foram observadas nas raízes de plântulas com 28 dias de idade crescidas no escuro. Nas raízes tuberosas de plantas com 10 meses de idade, verificou-se uma pequena quantidade de rotenona concentrada principalmente na região do colo. Porém, pachyrhizina não foi encontrada na raiz tuberosa de P. tuberosus. Sendo assim é possível utilizar na alimentação somente a raiz tuberosa sem a casca e sem o tecido da região do colo da raiz. Rotenona nas concentrações de 10-2M, 10-3M e 10-4M e pachyrhizina a 10-4M não afetaram significativamente as porcentagens finais de germinação de sementes mantidas na luz e escuro contínuos. Foi observado, também, que rotenona e pachyrhizina, nas concentrações utilizadas neste trabalho, não afetaram o desenvolvimento em peso de matéria fresca e comprimento dos eixos embrionários isolados dos cotilédones, mantidos na luz e escuro contínuos. Portanto, sugere-se que estes isoflavonóides não interferem no desenvolvimento inicial da planta de P. tuberosus. Nos experimentos com mitocôndrias isoladas de P. tuberosus, os resultados mostram que rotenona e pachyrhizina nas concentrações utilizadas, adicionadas ao meio de reação, não inibem o consumo de oxigênio em plântulas estioladas do Jacatupé. Sendo assim, supõe-se que estas substâncias, não interferem no transporte eletrônico da cadeia respiratória na mitocôndria desta espécie
Doutorado
Doutor em Ciências Biológicas

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Hidalgo, Nicho Eduardo Alejandro. "Toxicidad de la mezcla binaria de los plaguicidas metomilo y rotenona en la “lenteja de agua” Lemna minor (Linnaeus, 1758)." Bachelor's thesis, Universidad Ricardo Palma, 2015. http://cybertesis.urp.edu.pe/handle/urp/698.

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Se evaluó la toxicidad individual y binaria de los plaguicidas metomilo y rotenona en la macrofita Lemna minor (Linnaeus, 1753) para determinar la acción sinérgica o antagónica de una mezcla equitóxica. Los ensayos se realizaron bajo condiciones de laboratorio (T 29 ± 2°C; H 48,6 ± 9,4 %) y los resultados fueron analizados con los programas estadísticos BMDS® y Probit para calcular la concentración efectiva media (CE50) a través de los parámetros Área de la Fronda (AF) y Nuevas Frondas (NF). Los resultados sugieren una mayor precisión al utilizar el Método del Punto de Referencia del programa BMDS® para el cálculo de la concentración efectiva. Adicionalmente, se calculó la concentración total de clorofila (CTC) y peso húmedo (PH) para determinar la inhibición del crecimiento (Ir). Del mismo modo, se realizó una comparación entre los valores NOAEL (nivel de efecto no observado) y LOAEL (nivel bajo de efecto observado) versus los valores de BMDL (límite inferior del punto de referencia) y BMD (nivel de variación en el punto de referencia), respectivamente. El análisis muestra que existe una mayor precisión al emplear los valores BMD y BMDL. La acción fitotóxica varió según el parámetro analizado. La CE50 mostró mayores valores en el parámetro NF (1079,22 mg·L-1 para rotenona; 7147,42 mg·L-1 para metomilo; 597,904 mg·L-1 mezcla binaria: metomilo y 298,93 mg·L-1 mezcla binaria: rotenona) que en el parámetro AF (782,173 mg·L-1 para rotenona; 6919,79 mg·L-1 para metomilo; 629,513 mg·L-1 mezcla binaria: metomilo y 314,754 mg·L-1 mezcla binaria: rotenona). Finalmente, el modelo de concentración-adición mostró que la acción fitotóxica de la mezcla de ambos plaguicidas en Lemna minor tiene un efecto sinérgico. Macrophyte Lemna minor (Linnaeus, 1753) was used to evaluate the phytotoxicity of the individual and mix action of methomyl and rotenone pesticides under laboratory conditions (Temperature 29 ± 2°C; Humidity 48,6 9,4 %). The taken measures to establish half effective concentration (EC50) were the frond area (AF) and production of new fronds (NF). In this study, BMDS® and Probit stadistical data analyses were used to compare the results about effective concentration. Results suggest Benchmark dose method of BMDS® program was more effective than Probit program when EC50 were determined. Additionally, total chlorophyll concentration (CTC) and humidity weight (PH) parameters were calculated to determinate the growth inhibition (Ir). Likewise, NOAEL (no observed adverse effect level) and LOAEL (low observer adverse effect level) were compared with BMDL (lower bench mark dose) and BMD (Bench mark dose), respectively. BMD and BMDL values were more accurate than NOAEL and LOAEL values. Phytotoxic action varied according the parameter. EC50 values of Lemna minor showed poor sensibility to methomyl pesticide with an elevated concentration in both parameters (6919,79 mg•L-1 and 7147,42 mg•L-1 for AF and NF, respectively). Results of rotenone pesticide were lower than methomyl, with 1079,22 mg•L-1 (NF) and 782,173 mg•L-1 (AF). Finally, the mix toxicity was 597,904 mg•L-1 (methomyl: NF), 298,93 mg•L-1 (rotenone: NF), 629,513 mg•L-1 (methomyl: AF) and 314,754 mg•L-1 (rotenone: AF). For synergy calculation, Concentration-Adition value was used, concluding a higher synergism.

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Marangoni, Alessandra. "Extração de rotenona com fluido em estado supercrítico em escala semi-industrial." reponame:Repositório Institucional da UFSC, 2012. http://repositorio.ufsc.br/xmlui/handle/123456789/95838.

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Tese (doutorado) - Universidade Federal de Santa Catarina, Centro Tecnológico, Programa de Pós-Graduação em Engenharia Química, Florianópolis, 2011
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A busca por novas alternativas para um uso mais sustentável nos cultivos agrícolas é de fundamental importância para uma produtividade economicamente viável e ecologicamente aceitável. Na agricultura atual o uso de inseticidas e imprescindível, não existe cultivo sem aplicação de um bom controle de pragas. No esforço de controlar os insetos, o uso de inseticidas representa gastos da ordem de bilhões de dólares. Os produtos mais utilizados para essa finalidade são os fosforados, piretróides e os organoclorados. Esses inseticidas químicos deixam resíduos, contaminam solos, rios e os alimentos. Como são de amplo espectro, matam todas as classes de insetos que provocam desequilíbrios ambientais. Além disso, o seu uso frequente causa resistência nos insetos, o que demanda constante de aplicações e em maiores quantidades. A necessidade de outros métodos mais eficientes e menos agressivos ao homem e ao ambiente tem estimulado a busca por novos inseticidas. Na natureza várias plantas apresentam compostos com ação inseticida e, na maioria das vezes, esses extratos botânicos têm um efeito tóxico somente contra o inseto. Uma dessas substâncias com ação tóxica sobre animais de sangue frio é a rotenona. Essa molécula chegou a ser muito utilizada como inseticida até a Segunda Guerra Mundial, quando substituída pelos inseticidas DDT, HCH e, mais tarde, pelos organofosforados. Ela faz parte de um grupo importante de metabólicos secundários provenientes dos isoflavónoides. São muitas as técnicas de extração desta biomolécula, mas elas são pouco estudadas em escala industrial. A necessidade de alternativas para o controle das pragas na agricultura aliada às técnicas sustentáveis que não agridam o meio ambiente e nem causem mal ao homem é de fundamental importância para o crescimento do setor. Assim, o objetivo deste trabalho foi estudar a obtenção de rotenona em escala industrial. O método de extração estudado foi de extração supercrítica com CO2 como solvente e etanol como cossolvente. Para determinação de qual espécie apresenta melhor rendimento de rotenona estudou-se duas espécies vegetais: Derris elliptica e Tephrosia candida. Foram realizados experimentos em escalas laboratoriais com testes exploratórios para a definição dos parâmetros utilizados na escala industrial. Os experimentos em escala industrial realizaram-se nas condições que apresentaram o melhor resultado na escala-piloto e com espécie vegetal com melhor rendimento de extrato de rotenona. Os resultados indicam que a espécie vegetal Derris elliptica apresentou maior rendimento em percentagem extrato (g/g). Na escala laboratorial obteve-se esse resultado com uma pressão de trabalho de 100 bar e 60 ?C com etanol 92,8?GL m em extratores de 30 litros.

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Moreira, Camila Guimarães. "Padronização do modelo animal de parkinsonismo induzido por infusão de rotenona na substância negra pars compacta." reponame:Repositório Institucional da UFPR, 2012. http://hdl.handle.net/1884/28330.

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PEREIRA, Jos? Roberto. "Avalia??o da efici?ncia do extrato de ra?z Dahlstedti pentaphylla (Leguminosae, Papilionoidae, Millettiedae) sobre Boophilus microplus (CANESTRINI, 1887) na Regi?o do Vale do Para?ba - S?o Paulo, Brasil." Universidade Federal Rural do Rio de Janeiro, 2004. https://tede.ufrrj.br/jspui/handle/jspui/1822.

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Laboratory and field trials were performed to evaluate the efficiency of Timb? root extract (Dahlstedtia pentaphylla) (Taub). Burk. (Leguminosae, Papilionoidae, Millettiedae) on samples of Boophilus microplus (Canestrini, 1887) in bovines of the Para?ba Valley region ? S?o Paulo, Brasil. The ?in vitro? trials were carried out using immersion of engorged females, and ?in vivo? on bovines in the field by means of artificial infestation. The standard dilution was made from one part of root powder and three parts of ethanol this was considered the 100% solution. To determine the more efficient solvent to extract rotenone from the root, laboratory trials were conducted on B. microplus engorged females with in three solvents: water, ethanol a.p. and acetone a.p. The laboratory trials permitted the calculation of lethal doses at 90% (LD90) and 50% (LD50) for larvae between seventh and fourtheenth days of application and efficient concentrations at 90% (EC90) and 50% (EC50) on strain local and Mozo with B. microplus engorged females. For the larvae of the local strain (Para?ba Valley Regional Hub) LD50 calculated was 1:31,37 mL and LD90 was 1:85,24 mL. The EC90 for engorged females, of the same strain was of 1:10,19 mL and the EC50 1:34,94 mL. For the engorged females on the hypersersitive strain Mozo the EC90 was 1:23,91 mL and the EC50 1:60,46 mL. The mortality of engorged females in relation to the different kinds of solvents, was analyzed. In the field, the best results (76,10% of control) were obtained three days after application of the product extracted in ethanol, in 1:10, on animals. Then gradually between the seventh and fourteenth days the products lost efficiency, there was no significant difference between treatments and the control group after 21 days.
Foram realizados testes laboratoriais e de campo para avaliar a efici?ncia do extrato de ra?zes da planta Dahlstedtia pentaphylla (Taub.) Burk., (Leguminosae, Papilionoideae, Millettiae) sobre amostras de Boophilus microplus ( Canestrini, 1887 ) de bovinos da regi?o do Vale do Para?ba e da cepa sens?vel Mozo. Os testes foram efetuados ?in vitro?, pela t?cnica de imers?o de tel?ginas e ?in vivo?, sobre bovinos no campo, ap?s infesta??o artificial. As dilui??es foram obtidas a partir da extra??o de roten?ides utilizando?se uma parte de p? das ra?zes da planta para tr?s de etanol, sendo considerada padr?o 100%. Visando determinar o solvente mais eficiente para a extra??o de roten?ides das ra?zes, conduziram-se testes laboratoriais sobre tele?ginas de B. microplus em tr?s solventes: ?gua, etanol p.a e acetona p.a. Os testes laboratoriais permitiram calcular a Dose Letal 90% (DL90) e DL50 para larvas com idade entre sete e 21 dias e a Concentra??o Eficaz 90% (CE90) e CE50 sobre tele?ginas de B. microplus das cepas local e Mozo. Para as larvas da cepa local (Polo Regional do Vale do Para?ba) a DL50 calculada foi de 1: 231,37 mL e DL90 1: 85,24 mL. A CE90 para as tele?ginas, da mesma cepa, foi de 1:10,19 mL e a CE50 1: 34,94 mL. Para tele?ginas da cepa sens?vel Mozo a CE90 foi de 1: 23,91 mL e a CE50, 1: 60,46 mL. Analisou-se tamb?m a mortalidade das tele?ginas frente aos diferentes solventes. No campo os melhores resultados obtidos (76,10% de controle) foram obtidos tr?s dias ap?s a aplica??o do produto extra?do em etanol, na dilui??o 1: 10, sobre os animais. A partir da? gradualmente nos dias sete e quatorze os produtos foram perdendo efici?ncia, n?o apresentando mais diferen?a significativa entre os tratamentos e o grupo controle no dia +21.

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Brito, Ana Paula Amaral de. "Efeito dos extratos de valeriana officinalis na citotoxicidade da rotenona in vitro e na depressão alastrante cortical in vivo." reponame:Repositório Institucional da FIOCRUZ, 2015. https://www.arca.fiocruz.br/handle/icict/12702.

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Fundação Oswaldo Cruz, Centro de Pesquisas Gonçalo Moniz. Salvador, BA, Brasil
Universidade Federal da Bahia, Faculdade de Medicina. Salvador, BA, Brasil
Os astrócitos são o tipo celular mais numeroso no sistema nervoso central (SNC). Eles exercem suporte estrutural, trófico, e metabólico para neurônios e modulam a atividade sináptica. Então, o prejuízo nestas funções dos astrócitos pode influenciar na sobrevivência dos neurônios. De fato, numerosas evidências têm descrito a influência dos astrócitos no desenvolvimento de uma variedade de doenças neurodegenerativas. Neurotoxinas ambientais como rotenona, um inibidor específico do complexo I mitocondrial, provêem modelos de doenças neurodegenerativas tanto in vivo quanto in vitro. Sendo assim, a busca de novas substâncias com atividade neuroprotetora é atualmente o foco de estudos, e uma tendência crescente tem sido direcionada para plantas medicinais. Neste trabalho investigou-se a influência do extrato aquoso de Valeriana officinalis (V. officinalis) e da rotenona sobre os aspectos eletrofisiológicos do funcionamento cerebral, e o efeito citoprotetor dos extratos com éter de petróleo (PE) e metanol (MeOH) de V. Officinalis contra a toxicidade induzida pela rotenona. O estudo adotou uma abordagem que associa técnicas químicas, celulares e eletrofisiológicas. Ratos machos albinos, Wistar, adultos, em condições normais de nutrição, foram divididos em: grupo valeriana, tratados, por gavagem, com extrato aquoso de valeriana (250 mg/kg/dias) durante 15 dias; grupo rotenona, tratados, por via subcutânea, com rotenona (10 mg/kg) durante 7 dias; grupo valeriana + rotenona, submetidos a ambos tratamentos. Os respectivos controles foram igualmente tratados com solução salina ou solução de 1% de Tween-80 em água. Após o período de tratamento, os animais foram anestesiados, submetidos à trepanação seguida do registro da depressão alastrante cortical (DAC), na superfície do córtex cerebral, por 4 horas. Para avaliação da citoxicidade da rotenona e da atividade citoprotetora dos extratos de V. officinalis foram realizadas análises de viabilidade celular através da redução do brometo de 3-(4,5-dimetiltiazol-2-il)-2,5-difeniltetrazolium (MTT) e visualização por microscopia de contraste de fase em células de glioma murino (C6) e humano (GL-15), além de astrócitos de rato como controle de células normais. Os animais tratados com rotenona apresentaram redução da velocidade de propagação DAC enquanto que os animais tratados com valeriana apresentaram um aumento da velocidade de propagação. No entanto, os animais tratados com rotenona e valeriana não apresentaram diferença estatística na velocidade de propagação da DAC quando comparado aos grupos controles. Os resultados demonstraram que a rotenona foi citotóxica nas linhagens testadas, reduzindo a viabilidade e alterando a morfologia celular de maneira dose-dependente. Os extratos de PE e MeOH de V. officinalis foram efetivos em aumentar a viabilidade celular, bem como reduzir as alterações morfológicas induzidas pela rotenona nas linhagens celulares testadas. A análise do RMN 1H dos extratos de V. Officinalis demonstrou a presença de substâncias terpenoides; esse resultado relaciona os efeitos de V. Officinalis a ação antioxidante. O extrato aquoso de V. Officinalis preveniu as alterações eletrofisiológicas induzidas pela rotenona. Os resultados corroboram com estudos pregressos que descrevem os extratos de V. officinalis com função citoprotetora, deixando esse composto muito mais próximo de testes que venham a confirmar sua efetividade em diversas modalidades terapêuticas.
Astrocytes are the most numerous cell type in the central nervous system (CNS). They provide structural, trophic and metabolic support to neurons, and they modulate synaptic activity. Accordingly, impairment in these astrocyte functions can critically influence neuron survival. Indeed, several evidences have presented the influence of astrocytes for the development of a variety of neurodegenerative disorders. Environmental neurotoxins such as rotenone, a specific inhibitor of mitochondrial complex I that generates reactive oxygen species (ROS), provide models of neurodegenerative disorders both in vivo and in vitro. Thus, the search for new substances with neuroprotective activity is currently the focus of studies, and a growing trend has been directed at medicinal plants. In this study, we investigated the influence of of Valeriana officinalis (V. officinalis) and rotenone in the brain function through neurophysiological aspects, and the citoprotective effect of petroleum ether (PE) and methanol (MeOH) extracts of V. officinalis against rotenone-induced toxicity. The study adopted an approach that combines chemical, cellular and eletrophisiological techniques. Wistar male rats (adults), in normal conditions of nutrition, were divided in: valerian group, treated by gavage, for 15 days, with 250 mg/kg/day of the aqueous extract of V. officinalis; rotenone group, treated with s.c. injections at the daily dose of 10 mg/kg for 7 days; rotenone + valerian group treated with both substances. The control groups were treated equally with saline solution or 1% Tween-80 solution in water. After the treatment period, the cortical spreading depression (CSD) was recorded for 4 h at 2 cortical points in the parietal region. In order to investigate the rotenone-induced citotoxicity and the antioxidant activity of V. officinalis extracts, cell viability assays were performed through the reduction of 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), and visualization by phase contrast microscopy in rat glioma C6 cells and human glioblastoma GL-15 cells, as well as in rat astrocytes for comparison. The rotenone treated-animals presented lower mean CSD velocities, whereas CSD velocities were higher in the valerian-treated animals. When compared to the control animals, the treatment with rotenone plus valerian revealed no significant difference. The results demonstrated that rotenone was cytotoxic in the cell lines tested, reducing the cell viability and changing the cell morphology in a dose-dependent manner. The PE and MeOH extracts of V. officinalis were effective in increase cell ciability and reduce the rotenone-induced morphological changes in the tested cell lines. The 1H NMR analysis of V. Officinalis extracts showed the presence of terpenoid substances; this result relates the effects of V. Officinalis antioxidant action. The results corroborate previous studies describing the V. officinalis extracts with cytoprotective function, leaving the compound much closer to tests that will confirm their effectiveness in various therapeutic modalities

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Alecio, Marcio Rodrigo. "Atividade biológica de extratos de timbó (Derris scandens Aubl. e Deguelia floribundus Benth)sobre Cerotoma tingomarianus Bechyné (Coleoptera: Chrysomelidae) E Spodoptera frugiperda (J. E. Smith, 1797) (Lepidoptera: Noctuidae)." Universidade Federal do Amazonas, 2012. http://tede.ufam.edu.br/handle/tede/3123.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico
The abundance, potential insecticide and evidence of synergism among the major constituents of timbo extracts (Derris and Deguelia) and the need to control of Cerotoma tingomarianus Bechyné (Coleoptera: Chrysomelidae) and Spodoptera frugiperda Smith (Lepidoptera: Noctuidae) stimulated the realization of this study, which aimed to evaluate the biological effects of timbo extracts and its purified fractions compared to rotenone, as well as combined in different concentrations, on adults of C. tingomarianus and S. frugiperda larvae. Samples timbo roots were collected of plants in the Acre and Amazonas states, and obtained extracts by hot extraction of dry material method. The timbo extracts were grouped into six distinct groups and the bioassays were carried out by means of topical contact, contact by contaminated surface (filter-paper) and intake of contaminated diet in a completely randomized design. The mortality values of two insect species were submitted to Probit analysis to determine the LC50, LD50 and LT50. The other variables were subjected to variance analysis, when possible, using the Scott-Knott test (P> 0.05) for grouping treatment means. The intoxication by intake of contaminated diet/leaves is the most effective mean of contact for adults of C. tingomarianus and S. frugiperda larvae. The toxicity of timbo species extracts is variable and is related to the chemical composition of the extracts, as well as at form of exposure and the target insect species. Rotenone alone was not toxic to adult C. tingomarianus and showed low toxicity to S. frugiperda larvae, enhancing their biological effects on the insects/larvae when associated with the fractions containing timbo extracts, constituent A, constituent B and deguelin. The toxicity of timbo extracts for C. tingomarianus adult may be related to the combined action of several constituents. Extracts containing high levels of rotenone and deguelin are indicators of toxicity to S. frugiperda larvae. The association the constituent A with constituent B probably causes mortalities in the pre-pupal and pupal weight of S. frugiperda. The extract of timbo G1 and G3 showed the highest toxicity to insects and can be considered as the most promising for the development of biotechnology products for the control of C. tingomarianus adults and S. frugiperda larvae.
A abundância, o potencial inseticida e indícios de sinergismo entre os constituintes majoritários de extratos de timbó (Derris e Deguelia) e a necessidade de controle de Cerotoma tingomarianus Bechyné (Coleoptera: Chrysomelidae) e de Spodoptera frugiperda Smith (Lepidoptera: Noctuidae) estimularam a realização desta pesquisa, que objetivou avaliar os efeitos biológicos de extratos de timbó e de suas frações comparados à rotenona purificada, isoladamente e combinados em diferentes concentrações, sobre adultos de C. tingomarianus e de lagartas de S. frugiperda. Foram coletadas amostras de raízes de plantas de timbó nos estados do Acre e do Amazonas e obtidos extratos a quente utilizando clorofórmio como solvente. Os extratos das plantas de timbó foram agrupados em seis grupos distintos e os bioensaios foram desenvolvidos pelas vias de intoxicação de contato tópico, de contato por superfície contaminada e por ingestão alimentar, com delineamento experimental inteiramente casualizado. Os valores de mortalidade das duas espécies de insetos foram submetidos à análise de Probit para determinação das CL50, DL50 e TL50. As demais variáveis foram submetidas à análise de variância, quando possível, utilizando-se o teste de Scott-Knott (P > 0,05) para agrupamento das médias dos tratamentos. A intoxicação por ingestão alimentar é a via de contato mais efetiva para adultos de C. tingomarianus e lagartas de S. frugiperda. A toxicidade dos timbós é variável e está relacionada à composição química dos extratos, a forma de exposição e a espécie de inseto alvo. A rotenona utilizada isoladamente não foi tóxica para adultos de C. tingomarianus e apresentou baixa toxicidade para lagartas de S. frugiperda, potencializando seus efeitos biológicos sobre as lagartas quando associada com as frações dos extratos de timbó contendo deguelina e os constituintes A e B. A toxicidade dos extratos de timbó para adultos de C. tingomarianus pode estar relacionada à atuação conjunta de diversos constituintes. Extratos com elevados teores de rotenona e deguelina são indicadores de toxicidade para lagartas de S. frugiperda. A associação do constituinte A com o constituinte B provavelmente provoca mortalidades na fase pré-pupa e o peso de pupa de S. frugiperda pode ser reduzido pela atuação conjunta de vários constituintes dos extratos de timbó. O constituinte A pode atuar como antagonista de mortalidade de lagartas, provocar deformações e afetar a viabilidade de adultos de S. frugiperda. Os extratos de timbó G1 e G3 apresentam a maior toxicidade para os insetos e podem ser considerados como os mais promissores para o desenvolvimento de produtos biotecnológicos para o controle de adultos de C. tingomarianus e de lagartas de S. frugiperda.

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Sudati, Jessie Haigert. "Avaliação do potencial terapêutico da Valeriana officinalis e do disseleneto de difenila frente à toxicidade induzida por rotenona em Drosophila melanogaster." Universidade Federal de Santa Maria, 2012. http://repositorio.ufsm.br/handle/1/4452.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico
Among various antioxidant therapeutic applications, neuroprotective action is highlighted sinceoxidative stress is recognized as one of the events involved in cell damage which occur in most of neurological disorders, including Parkinson s disease (PD). Consequently, the search for natural and/or synthetic antioxidants which may be effective in the treatment of neurological disorders has grown over the past years. In this context, several studies have shown the antioxidant potential of selenium organic compound diphenyl diselenide (DPDS) in vitro and in vivo, but there are still few studies talking about antioxidant activity of Valeriana officinalis (V. officinalis). Likewise, there is no research on the possible beneficial effects of these agents in models of neurological diseases such as PD using Drosophila melanogaster (D. melanogaster), an specie that has been used with great reliability in the reproduction of dopaminergic dysfunction models. Thus, the objective of this study was to evaluate the in vitro antioxidant activity of V. officinalis, as well as, the effect of supplementation of extract from roots of this plant and DPDS on behavioral and biochemical changes induced by pesticide rotenone exposure in D. melanogaster. As a result, we verify that: ethanolic extract from V. officinalis inhibited the generation of TBARS caused by various pro-oxidants agents in rat s brain homogenate in vitro, diminished deoxyribose degradation and generation of reactive oxygen species (ROS) caused by quinolinic acid (QA); flies exposed to rotenone were significantly lower than control group in behavioral tests of climbind and open-field (number of crossings and immobility time) and higher incidence of mortality. V. officinalis treatment was effective in reducing these effects, except against the decrease in number of crossings. Exposure to rotenone decreased in flies cell viability and non protein thiol content, but V. officinalis treatment normalized to the control levels. Rotenone increased mRNA expression on superoxide dismutase (SOD), catalase (CAT) and tyrosine hydroxilase (TH) enzymes, which were restored by treatment with V. officinalis; DPDS supplementation was not effective in offering protection against locomotor and biochemical alterations induced by rotenone. In addition, DPDS per se induced an increase in ROS production and decreased survival rate of flies. In general, data showed that V. officinalis may be a promising neuroprotective agent, since it was effective in reducing the oxidative damage caused by different neurotoxic agents and toxic effects caused by rotenone exposure. Thus, the use of this plant extract may be beneficial in reducing neurological disorders associated to the oxidative stress. In relation to the use of DPDS, further studies aimed at the concentrations used are necessary, given that the concentration tested in this work did not offer protection against rotenone damage effects, DPDS potentiated the effect of this pesticide on mortality and exhibited toxic effects per se. Overall, these results contribute to the advancement of research focused on the toxicology and pharmacology of natural and synthetic products and screening for agent that provide neuroprotection and may be promising to assist in the treatment of neurodegenerative diseases, including PD.
Dentre as várias aplicações terapêuticas dos antioxidantes, destaca-se a ação neuroprotetora, uma vez que, o estresse oxidativo (EO) é reconhecido como um dos eventos envolvidos nos danos celulares que ocorrem na maioria das doenças neurológicas, incluindo a doença de Parkinson (DP). Consequentemente, a procura por antioxidantes naturais e/ou sintéticos que possam ser eficazes no tratamento de distúrbios neurológicos tem crescido muito ao longo dos últimos anos. Neste contexto, vários trabalhos têm evidenciado o potencial antioxidante do composto orgânico de selênio disseleneto de difenila (DPDS) in vitro e in vivo; mas, ainda, são escassos estudos acerca da atividade antioxidante da planta Valeriana officinalis (V. officinalis). Da mesma forma, ainda não há pesquisas sobre os possíveis efeitos benéficos desses agentes em modelos de doenças neurológicas, como a DP, utilizando a Drosophila melanogaster (D. melanogaster), uma espécie que vem sendo usada com bastante confiabilidade na reprodução de modelos de disfunção dopaminérgica. Assim, o objetivo deste trabalho foi avaliar a atividade antioxidante in vitro da V. officinalis, bem como, os efeitos oriundos da suplementação com o extrato da raiz desta planta e com DPDS sobre alterações comportamentais e bioquímicas induzidas pela exposição ao pesticida rotenona em D. melanogaster. Como resultados, verificamos que o extrato etanólico de V. officinalis inibiu a geração de TBARS causada por diferentes agentes pró-oxidantes, em homogeneizado de tecido cerebral de rato in vitro; diminuiu a degradação da desoxirribose e a geração de espécies reativas de oxigênio (ERO), causada pelo ácido quinolínico (AQ); as moscas expostas à rotenona tiveram um desempenho significativamente inferior ao grupo controle nos testes comportamentais de escalada e campo-aberto (número de cruzamentos e tempo de imobilidade), bem como, uma maior incidência de mortalidade. O tratamento com V. officinalis foi eficaz em reduzir esses efeitos, exceto frente à diminuição do número de cruzamentos. A exposição à rotenona diminui a viabilidade celular e o conteúdo de tiol protéico das moscas, que foi normalizada aos níveis do controle pelo tratamento com V. officinalis. A rotenona aumentou a expressão de mRNA das enzimas Superóxido dismutase (SOD), Catalase (CAT) e Tirosina hidroxilase (TH) quando comparado ao grupo controle e a alteração observada na expressão da SOD e CAT foi restaurada pelo tratamento com V. officinalis; a suplementação com DPDS não foi eficaz em oferecer proteção contra as alterações locomotoras e bioquímicas induzidas por rotenona. Além disso, o DPDS induziu per se um aumento na produção de ERO e uma diminuição na taxa de sobrevivência das moscas. De forma geral, os dados obtidos mostram que a V. officinalis pode ser considerada um agente neuroprotetor promissor, uma vez que foi eficaz em reduzir os danos oxidativos causados por diferentes pró-oxidantes e os efeitos tóxicos causados pela exposição à rotenona. Assim, o uso do extrato desta planta pode ser benéfico na redução de complicações neurológicas associadas ao EO. Com relação ao uso do DPDS, mais estudos voltados para as concentrações utilizadas são necessários, tendo em vista que, na concentração testada neste modelo experimental, o mesmo não ofereceu proteção contra os efeitos danosos da rotenona, potencializou o efeito do pesticida sobre a taxa de mortalidade e exibiu efeitos tóxicos per se. De forma geral, esses resultados contribuem para o avanço das pesquisas voltadas para a toxicologia e farmacologia de produtos naturais e sintéticos e para a triagem de agentes que ofereçam neuroproteção e possam ser promissores para auxiliar na terapêutica de doenças neurodegenerativas, incluindo a DP.

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Zaminelli, Tiago. "Efeito tipo-antidepressivo e antioxidante do Ibuprofeno no modelo da Doença de Parkinson induzido por administração de Rotenona intraperitoneal em ratos." reponame:Repositório Institucional da UFPR, 2013. http://hdl.handle.net/1884/32032.

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Resumo: A doença de Parkinson idiopática (DP) é uma doença neurodegenerativa, que afeta aproximadamente 1% da população mundial acima de 55 anos, manifestando-se através de sinais motores e sintomas não-motores, como a depressão, decorrentes principalmente da neurodegeneração dos neurônios dopaminérgicos na substância negra pars compacta (SNpc). Dentre os possíveis mecanismos envolvidos nesta patologia, destacam-se a disfunção mitocondrial, neuroinflamação e o estresse oxidativo. Em nosso estudo foi avaliado o efeito do antiinflamatório não esteróide (AINE) ibuprofeno, um inibidor não seletivo da enzima ciclooxigenase, sobre o prejuízo motor e comportamento tipo-depressivo induzidos pela administração intraperitoneal de rotenona em ratos. Nossos resultados demonstram que a administração de rotenona (2,5 mg/kg, por 10 dias, i.p.), foi capaz de reduzir a imunoreatividade da enzima tirosina-hidroxilase na SNpc, enquanto que o pós-tratamento com ibuprofeno (15 mg/kg, por 22 dias, p.o.) bloqueou esta redução. Também demonstramos que a rotenona foi capaz de induzir déficit motor (hipolocomoção) e comportamento tipo-depressivo, sendo ambos revertidos pelo pós-tratamento com ibuprofeno. Além destes parâmetros, foi avaliado o estresse oxidativo induzido por esta toxina. A administração de rotenona promoveu depleção nos níveis de GSH na região do hipocampo, e também reduziu a atividade da catalase em ambas as regiões, hipocampo e estriado. O pós-tratamento com ibuprofeno bloqueou a depleção do GSH induzida pela rotenona, bem como, aumentou os níveis basais deste antioxidante na região do estriado. O ibuprofeno também restaurou a atividade da catalase. Assim, acreditamos que o efeito neuroprotetor do ibuprofeno contra a toxicidade induzida pela rotenona em nosso estudo seja decorrente de suas propriedades antioxidante e inibidora da COX.

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SILVA, Jamilka Leopoldina da. "Avaliação da atividade neuroprotetora do Eugenol em modelo experimental da Doença de Parkinson." Universidade Federal de Pernambuco, 2014. https://repositorio.ufpe.br/handle/123456789/17457.

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FACEPE
O crescimento da expectativa de vida média da população mundial é um dos maiores desafios da saúde pública contemporânea e tem íntima relação com o aumento na prevalência de doenças neurodegenerativas. A doença de Parkinson (DP) é um distúrbio neurológico progressivo, ligado à degeneração de neurônios dopaminérgicos nigroestriatais, de causas multifatoriais. Os sintomas são relacionados principalmente às funções de coordenação motora e cognição. Evidências demonstram que alterações mitocondriais e elevados níveis de estresse oxidativo estão fortemente associados ao desenvolvimento da DP. No presente estudo, foi avaliado o efeito neuroprotetor do eugenol (EUG) sobre as alterações comportamentais e bioquímicas induzidas pela administração sistêmica de rotenona (modelo experimental da doença de Parkinson) em ratos Wistar. Inicialmente, foi avaliada a atividade antioxidante in vitro (AAIV) do EUG através do método de captura do radical livre DPPH. O ensaio de toxicidade aguda do EUG foi realizado conforme OECD 420 (2001). A avaliação comportamental, após indução da DP em ratos, foi feita através dos testes: Campo aberto (CA), Rota Rod (RR), Labirinto em cruz elevado (LCE) e Catalepsia (CP). Ao final dos testes comportamentais, foram mensurados os níveis séricos de corticosterona (NSC), através de ensaio imunoenzimático (ELISA). O EUG apresentou considerável AAIV (IC50= 32,189 μg/mL) comparado ao padrão BHT (IC50= 64,63 μg/mL). A dose letal mínima do EUG em camundongos foi superior a 2 g/kg. A administração subcutânea de rotenona (2,5 mg/kg por 5 dias) causou significativa perda de peso corporal, déficit motor (teste de RR), rigidez muscular e aumento do tempo de acinesia (teste de CP), elevação dos níveis de ansiedade (teste de CA) e comprometimento da memória (teste do LCE) comparado ao grupo controle (C). O pré-tratamento diário com EUG (37,5 mg/kg, v.o.), uma hora anterior à administração da toxina, promoveu menor perda de peso corporal, melhoramento no desempenho motor e cognitivo, bem como redução nos níveis de ansiedade, comparado ao controle negativo (N). Além disso, o grupo pré-tratado com EUG apresentou, de maneira geral, padrões comportamentais semelhantes, porém melhorados, em relação ao controle positivo (L), pré-tratados com levodopa (4 mg/kg, v.o.). A queda nos níveis de ansiedade foi reafirmada através dos resultados obtidos na análise bioquímica. Os NSCs do grupo N foram significativamente maiores comparados ao grupo C. Não houve diferença significativa nos NSCs entre os grupos C e pré-tratados com EUG; e ainda, foi observado menor NSC nos animais pré-tratados com EUG em relação ao grupo L. Os resultados sugerem potencial efeito neuroprotetor do EUG frente à toxicidade induzida pela rotenona. Esse efeito, provavelmente relacionado à presença das atividades antioxidante e ansiolítica do composto, apresenta o EUG como um agente promissor na terapêutica e/ou prevenção da DP.
The increase in average life expectancy of the world population is a great challenge of contemporary public health and it presents close relation to the increase in the prevalence of neurodegenerative diseases. Parkinson's disease (PD) is a progressive neurological disorder linked to degeneration of nigrostriatal dopaminergic neurons caused by multiple factors, and the symptoms are mainly related to the functions of coordination and cognition. Evidences have shown that mitochondrial alterations and elevated levels of oxidative stress are strongly associated to the development of PD. In the present study, it was evaluated the neuroprotective effect of eugenol (EUG) on behavioral and biochemical changes induced by systemic administration of rotenone (an experimental model of Parkinson's disease) in rats. Initially, we evaluated the in vitro antioxidant activity (IVAA) of EUG by the method of capturing the free radical DPPH. The acute toxicity of EUG was performed according to OECD 420 (2001). A behavioral evaluation after induction of PD in rats was assessed through the following tests: open field (OF), Rota Rod (RR), elevated plus maze (EPM) and catalepsy (CP). At the end of behavioral testing, the corticosterone serum levels (CSLs) were measured by immunoassay (ELISA). EUG showed considerable IVAA (IC50= 32,189 μg/mL) compared to the standard BHT (IC50= 64.63 μg/mL). The minimum lethal dose of EUG in mice was higher than 2 g/kg. The subcutaneous administration of rotenone (2.5 mg/kg for 5 days) caused significant weight loss, motor impairment (RR test), muscle stiffness and increased length of akinesia (CP test), elevated levels of anxiety (OF test) and memory impairment (EPM test) compared to the control group (C). Daily pretreatment with EUG (37.5 mg/kg, p.o.), one hour before administration of the toxin, promoted less weight loss, improvement in motor and cognitive performances, as well as a reduction in anxiety levels compared to the negative control (N). Moreover, the EUG pretreated group showed, in general, similar behavioral patterns, but improved relative to the positive control (levodopa 4 mg/kg, p.o.). The reduction in anxiety levels was reaffirmed by the results obtained in biochemical analysis. CSLs of the N group were significantly higher compared to the C group. In CSLs, there was no significant difference between EUG pretreated and C groups; and, less CSL was observed in EUG pretreated group compared to the L group. The results suggest potential neuroprotective effect of EUG against the rotenone-induced toxicity. This effect is probably related to the presence of antioxidant and anti-anxiety activities of the compound. Therefore, EUG may be a promissory drug for the treatment and/or prevention of PD.

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LIMA, Geovanny Braga. "Avaliação in vitro do efeito genotóxico e neurotóxico da rotenona em populações neuronais de encéfalo de ratos." Universidade Federal do Pará, 2011. http://repositorio.ufpa.br/jspui/handle/2011/2595.

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FAPESPA - Fundação Amazônia de Amparo a Estudos e Pesquisas
A doença de Parkinson (DP) é uma doença neurodegenerativa, que afeta principalmente neurônios dopaminérgicos da substância negra que projetam para o estriado. A rotenona, um composto amplamente usado como pesticida, pode estar relacionada a influências ambientais que aumentam o risco do aparecimento da DP. Estudo com análise de danos no DNA, como o ensaio em eletroforese do cometa foi introduzido neste trabalho para uma melhor compreensão de efeitos neurotóxicos da rotenona em modelo experimental da DP. O teste do cometa foi aplicado em neurônios provenientes de culturas mesencefálicas mistas de ratos expostas a diferentes concentrações em dois tempos de exposição, 24 e 48 horas. A média do índice de dano dos cometas mostrou-se, segundo análise estatística, significativamente diferente em relação ao grupo controle em todas as concentrações de rotenona testadas e nas duas durações analisadas. No entanto, na análise comparativa do índice de dano considerando o tempo de exposição para concentrações equivalentes, somente 20 e 30 nano molares demonstraram diferença significativa entre 24 e 48 horas de exposição. Este trabalho demonstrou que, nas condições empregadas, o teste do cometa detectou danos no material genético sem alteração detectável no teste de viabilidade celular pelo MTT (5 nM de rotenona por 24h), sugerindo que alterações genotóxicas podem anteceder alterações de viabilidade celular em neurônios expostos à rotenona. Entretanto, não é possível afirmar se tais alterações possuem caráter irreversível ou não.
Parkinson’s disease is a neurogenerative disease that affects dopaminergic neurons of the substantia nigra whose neurons Project to the striatum. Rotenone is a compound widely used as pesticide and which has been implicated among the environmental factors that increase the risk of developing PD. An essay that evaluate DNA damage, such as the eletroforesis comet essay, was introduced in the present work, to better understand the neurotoxic effects of the rotenone in a experimental model of PD. The comet assay was applied to neurons from mixed mesencephalic cultures exposed to different concentrations of rotenone in two different exposure times, 24 and 48 hours. The mean comet damage index showed a significant difference between the control condition and all the rotenone concentrations tested in both exposure times. However, in the comparative analysis considering time exposure for equivalent concentrations, there was significant difference only with 20 and 30 nM rotenone concentrations. This study demonstrated that, in the experimental conditions used, the comet assay detected damage to the genetic material without detectable alterations in the MTT viability test (5 nM rotenone, 24h), suggesting that genotoxic alterations may precede viability alterations in rotenone-exposed neurons. It is not possible, however, to assure that such alterations are irreversible or not.

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Linard, Cybelle Façanha Barreto Medeiros. "Efeito neuroprotetor do extrato hidroetanólico de Anacardium occidentale e do ácido anacárdico no modelo experimental animal da doença de parkinson induzido por rotenona." Universidade Federal de Pernambuco, 2014. https://repositorio.ufpe.br/handle/123456789/11927.

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FACEPE (Fundação de Amparo à Ciência e Tecnologia do Estado de Pernambuco) CNPq (Conselho Nacional de Desenvolvimento Científico e Tecnológico)
O aumento da população idosa tem levado a uma crescente incidência de doenças neurodegenerativas em todo o mundo. O consumo de alimentos de origem vegetal e o uso das propriedades terapêuticas de muitas plantas destacam-se desde os primórdios da humanidade. Anacardium occidentale Linn, conhecido popularmente como cajueiro, é uma árvore nativa do Norte e Nordeste do Brasil. Seu pseudofruto possui elevado teor de vitamina A, do complexo B, C e compostos fenólicos. O ácido anacárdico, composto fenólico obtido a partir do Anacardium occidentale, possui propriedades terapêuticas tais como: antimicrobiana, gastroprotetora, anticarcinogênica e anti-inflamatória. Evidências in vitro e in vivo mostraram que tanto o Anacardium occidentale quanto o ácido anacárdico possuem baixa toxicidade e efeitos antioxidantes, sugerindo potencial uso terapêutico. Entretanto, nenhum desses estudos foi realizado para testar o efeito antioxidante da administração sistêmica do Anacardium occidentale e ácido anacárdico no sistema nervoso central em modelo experimental de doença de Parkinson. Neste estudo hipotetizamos que Anacardium occidentale e ácido anacárdico podem exercer neuroproteção no córtex cerebral e no sistema nigroestriatal contra o estresse oxidativo induzido pela rotenona. Ratos adultos foram tratados por via oral com extrato hidroetanólico de Anacardium occidentale (150 e 600 mg/kg), ácido anacárdico (1-100 mg/kg) ou veículo, 1 hora antes da administração de rotenona (3 mg/kg) por via subcutânea durante 5 dias consecutivos. O comportamento dos animais foi avaliado nos testes do campo aberto, rotarod, catatonia e labirinto em T. Os sinais de neurodegeneração na substância negra, lipoperoxidação no sistema nigroestriatal e córtex cerebral e dosagem da enzima superóxido dismutase total também foram avaliados. Os grupos tratados com Anacardium occidentale e ácido anacárdico melhoraram a neuromotricidade nos testes comportamentais e, nas doses de 150 e 600 mg/kg de Anacardium occidentale no córtex, diminuíram a lipoperoxidação, provocados pela rotenona, em 47 e 62%, respectivamente; no estriado, em 32 e 56%, respectivamente; e na substância negra, na dose de 600 mg/kg, em 76%. O aumento da atividade da enzima superóxido dismutase total foi detectada usando ácido anacárdico 25-100 mg/kg em todas as regiões analisadas. Este aumento variou de acordo com a região, correspondendo a cerca de 80% na substância negra, 53% no córtex cerebral e de 230% no corpo estriado. O ácido anacárdico também diminuiu sinais de neurodegeneração provocados pela rotenona na substância negra. A administração oral de Anacardium occidentale e ácido anacárdico impediram a neurotoxicidade induzida pela rotenona em ratos, em parte, devido à sua ação moduladora sobre a enzima superóxido dismutase total, reduzindo neurodegeneração no sistema nigroestriatal e no córtex cerebral.

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MARTINS, FILHO Arnaldo Jorge. "Modelo in vitro de parkinsonismo experimental induzido por rotenona: investigação de mecanismos de ação, neuroproteção e morte celular." Universidade Federal do Pará, 2011. http://repositorio.ufpa.br/jspui/handle/2011/2600.

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FAPESPA - Fundação Amazônia de Amparo a Estudos e Pesquisas
Evidências crescentes na literatura têm sugerido papel importante para os fatores ambientais, como a exposição a pesticidas, na patogênese da doença de Parkinson. Em animais experimentais, a exposição à rotenona, um pesticida e piscicida de uso comum, induz características de parkinsonismo através da inibição do complexo I mitocondrial. O objetivo deste estudo foi investigar a morte de neurônios induzida por rotenona utilizando culturas primárias mistas neurônio/glia derivadas de hipocampo e de mesencéfalo ventral de ratos, bem como o papel do Ca2+ na neste modelo experimental e a utilização de extrato aquoso de folhas de mogno com substâncias com alto poder antioxidante. A perda neuronal foi analisada com ensaios colorimétricos (MTT e LDH). Nossos resultados mostraram significativa redução na viabilidade celular após exposição à rotenona de maneira dependente de concentração, mas não dependente de tempo. Foi observada igual e elevada suscetibilidade em culturas mistas neurônio/glia derivadas de hipocampo e de mesencéfalo ventral ao agente neurotóxico. Em termos mecanicísticos, nossos resultados mostraram um papel discreto desempenhado pelo Ca2+ mitocondrial na neurodegeneração induzida por rotenona. Além disso, neste paradigma utilizado, verificamos que o extrato aquoso de folhas de mogno não promoveu proteção contra a toxicidade da rotenona, na concentração testada; ainda, promoveu efeito sinérgico em associação com rotenona. Verificou-se ainda que a rotenona, bem como o extrato de mogno promoveu indução de morte celular tanto por necrose quanto por apoptose, nas concentrações utilizadas. Os resultados deste estudo devem avançar nosso conhecimento sobre o mecanismo de ação de fatores ambientais na patogênese da doença de Parkinson.
Increasing evidence has suggested a role for environmental factors, such as exposure to pesticides, in the pathogenesis of Parkinson’s disease. In experimental animals the exposure to rotenone, a common herbicide and piscicide, induces features of parkinsonism by inhibiting the activity of mitochondrial complex I. Here we propose to investigate rotenone-induced death of neurons by using primary neuron-enriched and neuron-glia cultures from the rat hippocampus and ventral mesencephalon. The neuronal loss was evaluated with the colorimetric MTT assay. Our results showed significant reduction in the cell viability after exposure to rotenone in a dose- but not in a timedependent manner. We also discovered a remarkable feature of rotenone-induced degeneration of cultured neurons. The higher susceptibility was observed in neuron-glia cultures from the ventral mesencephalon, suggesting that the presence of glia, especially microglia, is an important factor contributing to neurodegeneration. Also, as showed by immunohistochemistry, this type of culture presented the higher density of tirosinahidroxilase (TH)-positive neurons. Mechanistically, our results with calcium blockers showed a minimal role played by external calcium, and an important synergistic influence of the ions from the internal stores in the rotenone-induced neurodegeneration. Indeed, in this study, we report that aqueous extract of mahogany leaves didn’t protect against the rotenone-induced toxicity, in the used concentration; and promoted a synergistic effect when associated with rotenona. Finally, the mahogany leaves extract induced celular death both necrosis and apoptosis. The results of this study should advance our understanding of the mechanism of action for environmental factors in the pathogenesis of Parkinson’s disease.

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Morais, Lívia Hecke. "As alterações gastrointestinais e olfatórias precedem os sinais motores no modelo experimental da doença de Parkinson induzido pela rotenona." reponame:Repositório Institucional da UFSC, 2013. https://repositorio.ufsc.br/handle/123456789/107483.

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Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Ciências Biológicas. Programa de Pós-Graduação em Farmacologia, Florianópolis, 2013
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Existem hipóteses que o processo patológico da Doença de Parkinson inicia-se no Sistema Nervoso Entérico e no bulbo olfatório. Sendo assim, o objetivo deste estudo foi avaliar se a administração oral de um pesticida, rotenona, seria capaz de mimetizar a progressão temporal do parkinsonismo em camundongos, considerando os efeitos locais no trato gastrointestinal, efeitos comportamentais e neuroquímicos. Neste estudo, camundongos machos receberam administrações orais diárias de rotenona ou o veículo (carboximetilcelulose à 0,5%) por até 28 dias. Nossos resultados demonstram que o tratamento com a rotenona diminui a motilidade gastrointestinal associada à inflitração de leucócitos no cólon. Além disso, a rotenona prejudicou a discriminação e o reconhecimento olfativo, ao mesmo tempo em que induziu aumento taxa de renovação da serotonina no bulbo olfatório, sugerindo que as alterações neuroquímicas encontradas possam estar relacionadas ao prejuízo do processamento olfatório. No presente estudo, o comprometimento intestinal e olfatório precedem os danos motores, de maneira semelhante ao observado na Doença de Parkinson. Apesar disso, não houve diferença na concentração de monoaminas estriatais. O presente estudo demonstrou a importância do modelo experimental induzido pela administração oral de rotenona rotenona para compreensão dos mecanismos envolvidos nas alterações pré-motoras da Doença de Parkinson. Além disso, nossos resultados reforçam a importância da exposição a toxinas ambientais como fator de predisposição para a Doença de Parkinson. Ainda, esses resultados ressaltam a importância da via oral como porta de entrada para toxinas ambientais e o epitélio gastrointestinal como a primeira barreira de contato entre pesticidas e o organismo

Abstract: Accumulating evidence suggested that the pathological process of Parkinson´s disease starts in the enteric nervous system and in the olfactory bulb. However this hypothesis has not yet been fully investigated. Therefore, the aim of this study was to investigate the role of enteric nervous system and olfactory bulb in the onset of Parkinson?s disease induced by rotenone administration in mice. Male Swiss mice received daily oral administrations of rotenone 30 mg/kg or vehicle (0.5% carboxymetylcellulose) up to 28 days. Our results showed that rotenone was able to reduce the gastrointestinal motility, which was associated to leukocyte infiltration in the colon. Regarding the olfactory function, rotenone disrupted the discrimation and recognition abilities. At the same time, this treatment increased the serotonin turnover in the olfactory bulb, which suggests that these neurochemical alterations may be linked with the abnormal processing of odor stimulus. These alterations preceded the appearance of motor disability in our model, such as in Parkinson´s Disease clinical condition. Despite of it, no difference was found in monoaminergic concentrations in striatum. The current result indicated that rotenone model can be an important tool for studying premotor phase of parkinsonism in rodents. Moreover, our results reinforce the importance of environmental exposure to toxins and the key role of intestinal epithelium as the first point of contact with pesticides and chemical agents.

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Le?o, Anderson Henrique Fran?a Figueredo. "Ratos espontaneamente hipertensos (SHR) s?o resistentes a um modelo animal progressivo da doen?a de Parkinson: um estudo neuroqu?mico e comportamental." PROGRAMA DE P?S-GRADUA??O EM NEUROCI?NCIAS, 2016. https://repositorio.ufrn.br/jspui/handle/123456789/21553.

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Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico (CNPq)
Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES)
A Doen?a de Parkinson (DP) ? um dist?rbio motor relacionado ao envelhecimento que atualmente acomete de 1-2% da popula??o mundial acima dos 60 anos. No Brasil, estima-se que esta acometa aproximadamente 600 mil indiv?duos, configurando-se como uma enfermidade de import?ncia para pa?ses em processo de incremento da expectativa de vida. A epidemiologia da DP revela fatores de risco intr?nsecos e extr?nsecos ao paciente que definem a chance de desenvolvimento do dist?rbio. Muta??es pontuais e polimorfismos com significado funcional s?o tidos como fatores gen?ticos predisponentes, enquanto a exposi??o a pesticidas e toxinas destacam-se como fatores ambientais. No entanto, poucos estudos em modelos animais focam em investigar a intera??o entre estes fatores. Isto pode ser alcan?ado comparando-se os efeitos de subst?ncias indutoras de parkinsonismo em linhagens de ratos com diferentes contextos gen?ticos. Recentemente, o tratamento repetido com baixas doses de reserpina - um inibidor irrevers?vel do transportador vesicular de monoaminas (VMAT2) - foi proposto como um modelo progressivo para a DP. Sob este regime de tratamento, roedores apresentam, de forma progressiva, comprometimento motor, cognitivo, e altera??es neuroqu?micas compat?veis com a fisiopatologia da DP. Em paralelo, comparados a ratos Wistar, animais da linhagem SHR (Spontaneously Hypertensive Rats) s?o resistentes ? indu??o da discinesia oral pelo tratamento agudo com reserpina. Em vista destes achados, n?s buscamos avaliar se ratos SHR seriam resistentes aos d?ficits motores e altera??es neuroqu?micas quando submetidos ao modelo progressivo para DP induzido por reserpina. Portanto, n?s submetemos ratos Wistar e SHR ao tratamento agudo (1 mg/kg) ou repetido (15 inje??es de 0,1 mg/kg, em dias alternados) com reserpina e investigamos a progress?o dos d?ficits motores nas tarefas de catalepsia em barra, discinesia oral, e atividade espont?nea em campo aberto. Observamos ent?o que, para ambos os regimes de tratamento, animais SHR se mostram resilientes ao preju?zo motor em todas as dimens?es motoras avaliadas. Ainda, estas diferen?as se manifestaram tanto na lat?ncia para o surgimento do comprometimento motor como para a magnitude deste. Estas altera??es foram ainda acompanhadas por decr?scimo na express?o da tirosina hidroxilase (TH) e incremento na express?o de ?-sinucle?na na via nigro-estriatal de ambas linhagens submetidas ao tratamento com reserpina. Estas altera??es neuroqu?micas resultantes do tratamento com reserpina tamb?m se refletiram nos n?veis de monoaminas - dopamina e serotonina - na via nigro-estriatal destes animais. De modo geral, como no comportamento motor, animais SHR apresentaram atraso para a deple??o de monoaminas e menor magnitude deste efeito. Em conclus?o, os resultados aqui apresentados claramente corroboram a resili?ncia de ratos SHR ao modelo progressivo da DP. Estes achados exp?em novos alvos potenciais para as diferen?as neuroqu?micas, moleculares e gen?ticas na linhagem SHR relevantes para o estudo da susceptibilidade ? DP.
Parkinson?s disease (PD) is an aging-related progressive neurodegenerative disorder characterized by motor and non-motor symptoms, which affects 1-2% of the world population above 60 years old. In Brazil, this approximately 600 thousand people live with this disorder. Thus, PD is an important burden to countries with increasing life expectancy. The epidemiology of PD highlight intrinsic and extrinsic risk factors that are stochastic to the development of the disorder. Predisposing genetic factors comprise punctual mutations and polymorphisms with functional significance, while exposition to toxins is emphasizedas environmental factors. Nevertheless, few animal studies focus on the investigation of the interaction between these factors. Such may be accomplished by comparing the effects of substances that cause parkinsonism on rat strains with different genetic backgrounds. Recently, the repeated treatment with a low-dose of reserpine ? an irreversible inhibitor of the vesicular monoamine transporter (VMAT2) ? was suggested as a progressive model of PD. Rats under this treatment regimen show progressive catalepsy behavior, oral dyskinesia and spontaneous motor activity decrement. In parallel, compared to Wistar rats, SHR (Spontaneously Hypertensive Rat) are resistant to acute reserpine-induced oral dyskinesia. In view of these findings, we aimed to assess whether SHR would be resistant to repeated reserpine-induced motor and neurochemical deficits when submitted to the progressive model of PD. Thus, we submitted Wistar and SHR rats to the acute (1 mg/kg) or repeated (0,1 mg/kg, 15x, every other day) treatment with reserpine and investigated the progression of motor deficits in the catalepsy bar, oral dyskinesia, and spontaneous activity on the open field. Our results revealed that, for both treatment regimens, SHR rats were resistant to the motor impairment for all motor parameters assessed. Moreover, these differences were detected for both the latency to instauration and the magnitude of the impairment. The alterations were concomitant to a decrement in the optical density of tyrosine hydroxylase and an increment in ?-synuclein immunostaining by immunohistochemistryin the nigro-striatal pathway of both strains submitted to reserpine treatment. These neurochemical alterations resulted from reserpine treatment also reflected in the levels of monoamines ? dopamine and serotonin ? in the nigro-striatal pathway of these animals. Altogether, similarly to the motor behavior, SHR rats displayed lower magnitude and a delay to monoamine depletion. In conclusion, the current results clearly evidence the resilience of SHR to the repeated low-dose reserpine protocol. These findings uncover new potential underlying neurochemical, molecular and genetic differences in the SHR strain relevant to the study of susceptibility to PD.

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PASTRE, Adriana Sereniki. "Efeito neuroprotetor do extrato hidroalcoólico de Schinus terebinthifolius Raddi, na atividade comportamental e estresse oxidativo no modelo experimental da doença de Parkinson induzida por rotenona em ratos." Universidade Federal de Pernambuco, 2016. https://repositorio.ufpe.br/handle/123456789/25967.

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PASTRE, Adriana Sereniki, também é conhecido(a) em citações bibliográficas por: SERENIKI, Adriana
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Nos últimos anos, o aumento da população de idosos tem levado ao aumento na incidência de doenças neurodegenerativas em todo o mundo. Este fato tem proporcionado um interesse cada vez maior nos estudos que visam novas estratégias para a prevenção e cura dessas doenças. Várias evidências têm demonstrado que elevados níveis de estresse oxidativo, alterações mitocondriais, neuroinflamação e apoptose estão fortemente associados ao desenvolvimento de muitas doenças típicas do envelhecimento como Alzheimer, Parkinson e Huntington. Entretanto, as bases moleculares que desencadeiam estas doenças, ainda não estão totalmente compreendidas. De uma maneira geral, os principais mecanismos envolvidos no processo de neurodegeneração estão relacionados à excitotoxicidade mediada por aminoácidos excitatórios; formação de agregados proteicos; alterações da função mitocondrial; aumento intraneuronal de cálcio, proteínas pró-apoptóticas e mutações no DNA mitocondrial; bem como inibição de determinados complexos da cadeia respiratória mitocondrial. Além disso, mecanismos neuroinflamatórios, com ativação de células da glia e liberação de mediadores pró-inflamatórios, estão diretamente ligados à degeneração e à morte neuronal. Considerando que Schinus terebinthifolius (Anacardiaceae), conhecida popularmente como aroeira, apresenta propriedades anti-inflamatórias e antioxidantes, pareceu-nos atraente investigar se o extrato hidroalcoólico do caule dessa espécie possui efeito neuroprotetor nas alterações comportamentais e bioquímicas na doença de Parkinson (DP) experimental induzida por rotenona. Para tanto, cinco grupos (n=10/grupo) de ratos Wistar foram tratados por gavagem durante 7 dias consecutivos respectivamente com água + veículo do extrato (controle), água (rotenona) e doses crescentes de S. terebinthifolius (150, 300 e 600 mg/kg). Uma hora após o tratamento foi administrado rotenona (3 mg/kg, s.c.) a todos os grupos, exceto o grupo controle que recebeu o veículo (óleo de girassol 90%+10%DMSO). Decorridos 24h da administração de rotenona, foram realizadas avaliações comportamentais por meio dos testes de campo aberto, rotarod e testes de labirinto elevado-plus em ratos adultos Wistar. Também foram realizados testes in vitro e in vivo de atividade antioxidante pelo método de captura de radicais DPPH e peroxidação lipídica (TBARS), respectivamente. Os resultados mostram que a administração de rotenona (3 mg/kg, s.c.) produziu hipolocomoção, aumento da imobilidade, descoordenação muscular e déficit de memória, enquanto que a administração prévia do extrato de S. terebinthifolius impediu a rotenona de provocar comportamento disfuncional sobre a atividade locomotora, rotarod e retenção de memória. A análise bioquímica da substância nigra, striatum e córtex revelou que a rotenona aumentou significativamente a peroxidação lipídica, o que foi inibido pelo pré-tratamento com todas as doses de S. terebinthifolius. Dessa forma, conclui-se possível efeito neuroprotetor de S. terebinthifolius possivelmente mediada por meio da sua atividade antioxidante, indicando por sua vez um potencial benefício terapêutico desta espécie no tratamento da doença de Parkinson.
In recent years, the increase of the aging population has led to increased incidence of neurodegenerative diseases worldwide. This fact has given an increasing interest in studies aimed at new strategies for prevention and cure of these diseases. Several evidences have demonstrated that elevated levels of oxidative stress, mitochondrial changes, neuroinflammation and apoptosis is strongly associated with the development of many typical diseases of aging such as Alzheimer's, Parkinson's and Huntington's. However, the molecular basis that trigger these diseases are not yet fully understood. In general, the key mechanisms involved in the neurodegeneration process are related to excitotoxicity mediated by excitatory amino acids; formation of protein aggregates; changes in mitochondrial function; increase in intraneuronal calcium, proapoptotic proteins and mutations in mitochondrial DNA; and inhibition of certain complexes of the mitochondrial respiratory chain. Furthermore, neuroinflammatory mechanisms with glial cell activation and release of proinflammatory mediators are directly linked to degeneration and neuronal death. Whereas, Schinus terebinthifolius (Anacardiaceae), commonly known as aroeira, has anti-inflammatory and antioxidant properties, it seemed attractive to investigate whether the hydroalcoholic extract of the stem of this species has neuroprotective effect on the behavioral and biochemical changes in Parkinson's disease (PD) trial rotenone-induced. For this, five groups (n= 10/group) Wistar rats were treated by gavage for 7 consecutive days, respectively extract with water + vehicle (control), water (rotenone) and increasing doses of S. terebinthifolius (150, 300, and 600 mg/kg). One hour after treatment rotenone was administered (3 mg / kg, s.c.), all groups except control group received the vehicle (sunflower oil 90% + 10% DMSO). After 24 hours of rotenone management, behavioral assessments were conducted through the open field test, rotarod and elevated-plus maze tests in adult Wistar rats. They were also carried out in vitro and in vivo antioxidant activity by radical capture method DPPH and lipid peroxidation (TBARS), respectively. The results show that rotenone administration (3mg/kg, sc) produced hypolocomotion, increased immobility, muscle incoordination and memory deficit, whereas the prior administration of S. terebinthifolius extract prevented rotenone cause dysfunctional behavior on locomotor activity, rotarod and memory retention. Biochemical analysis of the substantia nigra, striatum and cortex revealed that rotenone significantly increased lipid peroxidation, which was inhibited by pre-treatment with all doses of S. terebinthifolius. Thus, it is concluded possible neuroprotective effect of S. terebinthifolius possibly mediated by its antioxidant activity, in turn indicating a potential therapeutic benefit of this species in the treatment of Parkinson's disease.

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Michelini, Luiz Guilherme Bueno 1983. "Caracterização do estímulo da produção mitocondrial de H2O2 por inibição parcial do Complexo I da cadeia respiratória = Stimulatory effects of a partial respiratory Complex I inhibition on mitochondrial H2O2 generation." [s.n.], 2014. http://repositorio.unicamp.br/jspui/handle/REPOSIP/313031.

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Orientador: Roger Frigério Castilho
Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas
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Resumo: A inibição parcial do Complexo I da cadeia respiratória mitocondrial em ratos tratados cronicamente com rotenona está associada com o desenvolvimento de características neuroquímicas, comportamentais e neuropatológicas da doença de Parkinson. Os objetivos deste trabalho foram (i) caracterizar os efeitos de uma inibição parcial do Complexo I por rotenona na produção de peróxido de hidrogênio (H2O2) por mitocôndrias de cérebro de ratos (MCR) em diferentes estados respiratórios e (ii) avaliar a suscetibilidade de MCR velhos (24 meses) à inibição do consumo de oxigênio (O2) e ao estímulo da produção de H2O2 por rotenona em comparação a MCR adultos (3-4 meses). A análise do potencial de membrana por citometria de fluxo em mitocôndrias isoladas indicou que a adição de rotenona promoveu uma inibição uniforme da respiração mitocondrial nestas organelas. Quando mitocôndrias foram incubadas na presença de uma baixa concentração de rotenona (10 nM) e de substratos geradores de NADH, o consumo de O2 foi reduzido de 45,9±1,0 para 26,4±2,6 nmol O2.mg-1.min-1 e de 7,8±0,3 para 6,3±0,3 nmol O2.mg-1.min-1 nos estados respiratórios 3 (respiração estimulada por ADP) e 4 (respiração de repouso), respectivamente. Nessas condições, a produção mitocondrial de H2O2 foi estimulada de 12,2±1,1 para 21,0±1,2 pmol H2O2.mg-1.min-1 e de 56,5±4,7 para 95,0±11,1 pmol H2O2.mg-1.min-1 nos estados respiratórios 3 e 4, respectivamente. Resultados similares foram observados ao comparar preparações mitocondriais enriquecidas com organelas sinápticas e não-sinápticas ou quando o íon 1-metil-4-fenilpiridina (MPP+) foi utilizado como inibidor de Complexo I mitocondrial. O estímulo da produção de H2O2 por rotenona nos estados respiratórios 3 e 4 foi associado a um aumento do estado reduzido de nucleotídeos de nicotinamida endógenos. Na respiração mitocondrial com succinato, onde a maior parte da produção de H2O2 se origina do fluxo reverso de elétrons do Complexo II para o I, baixas concentrações de rotenona inibiram a produção de H2O2. Rotenona não exerceu efeito sobre a eliminação mitocondrial de concentrações micromolares de H2O2. Em sinaptossomas intactos, observamos que rotenona 10 nM estimulou a liberação de H2O2 em 20,2±3,3% no estado respiratório basal. Ao compararmos MCR adultos e velhos, verificamos que o consumo de O2 no estado respiratório 3 e a atividade da citrato sintase foram 21,0±3,3% e 17,0±5,4% mais baixos em MCR velhos. Experimentos conduzidos na presença de diferentes concentrações de rotenona (5, 10 e 100 nM) demonstraram sensibilidade similar à inibição do consumo de O2 por rotenona no estado respiratório 3, com IC50 de 7,8±0,4 e 6,5±0,5 nM para MCR adultos e velhos, respectivamente. De acordo com esses resultados, o estímulo da produção de H2O2 observado foi similar em MCR adultos e velhos, tratadas com diferentes concentrações de rotenona. Concluímos que, uma inibição parcial do Complexo I pode resultar em uma crise energética e/ou estresse oxidativo mitocondrial, enquanto o primeiro evento predominaria numa situação de alta demanda de fosforilação oxidativa, o segundo ocorreria em condições de respiração de repouso. Em adição, os experimentos com ratos velhos indicaram que rotenona exerce efeitos similares no consumo de O2 e na produção de H2O2 em MCR adultos e velhos
Abstract: Partial inhibition of mitochondrial Complex I is associated with the development of neurochemical, behavioral, and neuropathological features of Parkinson's disease in rats chronically and systemically treated with rotenone. The aims of this work were (i) to characterize the effects of partial inhibition of respiratory Complex I by rotenone on H2O2 production by rat brain mitochondria in different respiratory states and (ii) to evaluate the susceptibility of brain mitochondria from old rats (24 month-old) to rotenone-induced inhibition of oxygen consumption and increased generation of H2O2 when compared with organelles from adult rats (3-4 month-old). Flow cytometric analysis of membrane potential in isolated mitochondria indicated that rotenone leads to uniform respiratory inhibition when added to a suspension of these organelles. When mitochondria were incubated in the presence of a low concentration of rotenone (10 nM) and NADH-linked substrates, oxygen consumption was reduced from 45.9±1.0 to 26.4±2.6 nmol O2.mg-1.min-1 and from 7.8±0.3 to 6.3±0.3 nmol O2.mg-1.min-1 in respiratory states 3 (ADP-stimulated respiration) and 4 (resting respiration), respectively. Under these conditions, mitochondrial H2O2 production was stimulated from 12.2±1.1 to 21.0±1.2 pmol H2O2.mg-1.min-1 and 56.5±4.7 to 95.0±11.1 pmol H2O2.mg-1.min-1 in respiratory states 3 and 4, respectively. Similar results were observed when comparing mitochondrial preparations enriched with synaptic or nonsynaptic organelles or when 1-methyl-4-phenylpyridinium (MPP+) ion was used as a respiratory Complex I inhibitor. Rotenone-stimulated H2O2 production in respiratory states 3 and 4 was associated with a high reduction state of endogenous nicotinamide nucleotides. In succinate-supported mitochondrial respiration, where most of the mitochondrial H2O2 production relies on electron backflow from Complex II to Complex I, low rotenone concentrations inhibited H2O2 production. Rotenone had no effect on mitochondrial elimination of micromolar concentrations of H2O2. In intact synaptosomes, we observed that 10 nM rotenone stimulated H2O2 release by 20.2 ± 3.3% under basal respiratory state. When comparing isolated brain mitochondria from adult and old rats we observed that oxygen consumption under respiratory state 3 and citrate synthase activity were 21.0±3.3% and 17.0±5.4% lower in mitochondria from old rats. Experiments conducted in the presence of different rotenone concentrations (5, 10 and 100 nM) showed that brain mitochondria from adult and old rats have similar sensitive to rotenone-induced inhibition of oxygen consumption in respiratory state 3, with IC50 of 7.8±0.4 and 6.5±0.5 nM for adult and old rats, respectively. In line with these results, similar stimulations in H2O2 production were observed in mitochondria from adult and old rats treated with different concentrations of rotenone. We conclude that partial Complex I inhibition may result in mitochondrial energy crisis and oxidative stress, the former being predominant under oxidative phosphorylation and the latter under resting respiration conditions. Rotenone exerts similar effects on oxygen consumption and H2O2 production by isolated brain mitochondria from adult and old rats
Mestrado
Biologia Estrutural, Celular, Molecular e do Desenvolvimento
Mestre em Ciências

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Santos, Pietro Araújo dos. "Efeito do 8-metoxipsoraleno (8-mop) na citotoxicidade da rotenona sobre células do sistema nervoso central, um modelo de doença de parkinson in vitro." reponame:Repositório Institucional da FIOCRUZ, 2015. https://www.arca.fiocruz.br/handle/icict/11852.

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Universidade Federal da Bahia. Fundação Oswaldo Cruz. Centro de Pesquisas Gonçalo Moniz. Salvador, BA, Brasil
Doença de Parkinson (DP) é caracterizada por uma perda seletiva e profunda dos neurônios dopaminérgicos da substância nigra pars compacta (SNpc) do mesencéfalo, acompanhada pela espoliação de dopamina no corpo estriado. A maioria dos casos de DP apresenta etiologia multifatorial, com a presença de componentes genéticos e ambientais. Embora existam diferentes causas possíveis, a patogênese da desordem parece convergir para mecanismos relacionados à disfunção mitocondrial, estresse oxidativo e mau enovelamento proteico. Um modelo estabelecido na literatura para estudo desta doença, tanto in vitro quanto in vivo é a administração de rotenona, um pesticida derivado de plantas que inibe o complexo I mitocondrial e favorece a geração de espécies reativas de oxigênio (ERO), levando a uma espoliação de glutation reduzido (GSH) através do processo de detoxificação destes compostos eletrofílicos, catalisados por glutation S-transferases (GSTs). Sendo assim, a busca por novas substâncias com atividade neuroprotetora é atualmente o foco de estudos, e metabólitos isolados de plantas podem ser fontes destas moléculas. Dessa forma, o 8-metoxipsoraleno (8-MOP), uma furocumarina, foi testado como um possível agente protetor sobre a citotoxicidade causada pela rotenona em modelos in vitro de gliomas, considerando o papel do glutation neste processo. O estudo adotou uma abordagem que associa técnicas bioquímicas e de biologia celular. Ensaios de viabilidade celular foram realizados em células de glioma murino (C6) e glioblastoma multiforme humano (U251) através da redução do brometo de 3-(4,5-dimetiltiazol-2-il)-2,5-difeniltetrazolium (MTT), e visualização por microscopia de contraste de fase. O tipo de morte celular provocada pela rotenona nas células U251 foi realizado por marcação com anexina V e iodeto de propídeo (IP), seguido por quantificação por citometria de fluxo. A determinação do conteúdo de GSH intracelular após tratamento com rotenona e 8-MOP foi visualizado por marcação com monoclorobimano (MCB) nas linhagens C6 e U251. Os resultados demonstraram que a rotenona foi citotóxica em ambas as linhagens, reduzindo a viabilidade e alterando a morfologia celular, enquanto que o 8-MOP não apresentou atividade citotóxica. Contudo, o tratamento com o 8-MOP não foi capaz de proteger as células contra os efeitos deletérios da rotenona. No estudo do tipo de morte celular, a porcentagem de células marcadas com anexina V foi maior nos grupos tratados com rotenona, demonstrando que a morte celular ocorre principalmente por apoptose. A análise com MCB demonstrou que a rotenona espoliou GSH, porém o pré-tratamento com 8-MOP inibiu a espoliação. Embora o 8-MOP não tenha sido bem sucedido na proteção das células, a manutenção do conteúdo de GSH corrobora com estudos prévios que descrevem este composto como um potencial inibidor de GST, uma atividade farmacológica que deve ser testada para confirmar a sua eficácia como agente terapêutico.
Parkinson’s disease (PD) is characterized by a profound and selective loss of dopaminergic neurons in the substantia nigra pars compacta (SNpc) accompanied by midbrain dopamine depletion in the striatum. Most cases of PD present multifactorial etiologies, with the presence of genetic and environmental components. Although there are different possible causes, the pathogenesis of the disorder seems to converge to mechanisms related to mitochondrial dysfunction, oxidative stress and bad protein folding. An established model in the literature to study this disease, both in vitro and in vivo is rotenone administration, a pesticide derived from plants that inhibits the mitochondrial complex I and favors the generation of reactive oxygen species (ROS), leading to reduced glutathione (GSH) depletion through the detoxification process of this electrophilic compound catalyzed by glutathione S-transferases (GSTs). Thus, the search for new substances with neuroprotective activity is currently the focus of studies, and plant isolated metabolites can be sources of these molecules. Thus, 8-methoxypsoralen (8-MOP), a furocoumarin, was tested as a potential protective agent on the cytotoxicity caused by rotenone in glioma cells in vitro models, considering the role of glutathione in the process. The study adopted an approach that combines biochemical and cell biology techniques. Cell viability assays were performed in murine glioma cells (C6) and human glioblastoma (U251) cells through the reduction of 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), and visualization by phase contrast microscopy. The type of cell death caused by rotenone in U251 cells was performed by staining with annexin V and propidium iodide (PI) followed by flow cytometric quantitation. The determination of intracellular GSH content after treatment with rotenone and 8-MOP was visualized by staining with monochlorobimane (MCB) in the lineages U251 and C6. The results demonstrated that rotenone was cytotoxic to both cell lineages, reducing the viability and changing the cell morphology, whereas the 8-MOP did not show cytotoxic activity. However, the treatment with 8-MOP was not able to protect cells against the deleterious effects of rotenone. In the type of cell death studies, the percentage of cells stained with annexin V was higher in the groups treated with rotenone, demonstrating that cell death occurs primarily by apoptosis. The analysis with MCB has shown that rotenone depleted GSH, but pre-treatment with 8-MOP inhibited the depletion. Although the 8-MOP has not been successful in protecting cells, the maintenance of GSH content corroborates with previous studies that describe this compound as a potential inhibitor of GST, a pharmacological activity that should be tested to confirm its effectiveness as a therapeutic agent.

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Santos, Nicole Francisca Henriques dos. "Injeção de rotenona, L-butionina sulfoximina e 6-hidroxidopamina no estriado dorsolateral como modelo de Parkinson experimental : alterações no equilíbrio postural e sinalização nitrérgica." reponame:Repositório Institucional da UFABC, 2016.

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Orientadora: Profa. Dra. Marcela Bermudez Echeverry
Dissertação (mestrado) - Universidade Federal do ABC, Programa de Pós-Graduação em Neurociência e Cognição, 2016.
A Doença de Parkinson (DP) é caracterizada por uma degeneração progressiva dos neurônios dopaminérgicos na substância negra e pela presença de 4 sinais cardinais, bradicinesia, rigidez muscular, tremor em repouso e instabilidade postural. Sua etiologia ainda é desconhecida, no entanto, o aumento do estresse oxidativo é uma das hipóteses a ser analisada. Existe um interesse cada vez maior em compreender o papel funcional e comportamental do estriado dorsolateral (CPU-DL), principalmente sobre o controle do equilíbrio postural. Dessa forma, o presente projeto se propôs a avaliar o efeito de diferentes toxinas, 6-hidroxidopamina (6-OHDA), L-butionina-sulfoximina (BSO) e a rotenona, sobre o CPU-DL e a resposta compensatória do sistema nitrérgico de forma tempo dependente. Foram utilizados ratos Wistar adultos, todos os procedimentos foram aprovados pelo CEUA-UFABC (Protocolo 035/2014). O Estudo 1 foi separado em 2 fases, no experimento 1.1 os animais foram divididos em 3 grupos, os quais receberam microinjeções no CPU-DL direito de 6- OHDA, BSO ou salina, sendo avaliados comportamentalmente 5 dias após a cirurgia e sacrificados no 6º dia. No experimento 1.2 os animais foram divididos em 3 grupos, os quais foram submetidos a uma dupla lesão, recebendo 6-OHDA no CPUDL + salina no PPTg, 6- OHDA no CPU-DL + BSO no PPTg ou salina no CPU-DL + salina no PPTg. Os animais do experimento 1.2 foram avaliados entre os 15º e 44º dias pós cirúrgico, sendo eutanasiados no 45º. No segundo estudo desenvolvido, os animais foram divididos em 5 grupos, os quais receberam 2 microinjeções no CPU-DL direito de rotenona (3mM, 5mM ou 9mM), DMSO (25% - veículo) ou salina, sendo avaliados entre os dias 15º e 44º pós cirúrgicos e sacrificados no 45º dia. Foram utilizados na avaliação comportamental os testes: comportamento rotatório induzido por apomorfina e anfetamina, teste de suspensão na grade, teste da cauda suspensa, teste do cilindro, equilíbrio vertical e labirinto em cruz elevado. Vinte e quatro horas após as análises comportamentais os animais foram sacrificados e procedimentos para analise imunohistoquímica foram realizados. No experimento 1.1 não se detectou alteração comportamental significativa, entretanto, no experimento 1.2 observou-se uma redução na performance dos grupos tratados em relação ao controle salina. Nossos resultados sugerem que tanto a 6-OHDA como o BSO, quando aplicados no CPU-DL, diminuem a expressão de TH+ na região CPU-DL e CPU-dorsomedial (CPU-DM), com aumento da expressão para a proteína nNOS no CPU-DL, sendo que o grupo 6-OHDA também mostrou aumento no CPUDM e núcleo accumbens. Por outro lado, um aumento escasso na expressão da proteína nitrotirosina foi observado no grupo BSO, no CPU-DM e CPU-ventrolateral (CPU-VL). A avaliação com maior intervalo de tempo realizada com as mesmas toxinas, indicou um possível papel neuroprotetor da injeção de BSO no PPTg contra o efeito neurotóxico da 17 injeção de 6- OHDA na CPU-DL. O segundo estudo desenvolvido corrobora uma potencial qualidade preditiva da microinjeção estriatal de rotenona como modelo de hemiparkinsonismo, pois foi capaz de mimetizar sintomas motores relacionados ao equilíbrio postural (rotarod, grade e equilíbrio vertical) e imunohistoquímicos, com aumento da expressão de nNOS e diminuição da expressão da TH+ de forma dose dependente no CPU e na substância negra. Nossos resultados sugerem que determinadas neurotoxinas, embora pouco exploradas, quando administradas via intra-estriatal, revelaram-se potencialmente efetivas para a indução de alterações no equilíbrio postural em modelos experimentais; corroborando portanto, uma possível interação do sistema dopaminérgico nigro-estriatal atrelado a um desbalanço do sistema nitrérgico, responsável pelo estresse oxidativo/nitrosativo relacionado aos processos neurodegenerativos. Neste sentido novos estudos devem ser conduzidos para uma melhor compreensão e elucidação da etiopatogenia da DP, além de novas perspectivas para futuras estratégias terapêuticas.
Parkinson's disease (PD) is characterized by progressive degeneration of dopaminergic neurons in the substantia nigra and the presence of four cardinal signs, bradykinesia, muscular rigidity, resting tremor, and postural instability. Its etiology is still unknown, however, increased oxidative stress is one of the hypotheses to be analyzed. There is a growing interest in understanding the functional and behavioral role of the dorsolateral striatum (CPU-DL), mainly on the control of postural balance. Thus, this project aimed to evaluate the effect of different toxins, 6-hydroxydopamine (6-OHDA), L-buthionine sulfoximine (BSO) and rotenone on the CPU-DL and the compensatory response nitrergic system time dependent manner. Adult Wistar rats were used, all procedures were approved by CEUA-UFABC (Protocol 035/2014). The first study was separated into two phases in the experiment 1.1 the animals were divided into 3 groups, which were microinjected on the CPU-DL right of 6- OHDA, BSO or saline, being evaluated behaviorally 5 days after surgery and sacrificed on the 6th day. In the 1.2 experiment the animals were divided into 3 groups, which were subjected to a double lesion, receiving 6-OHDA in CPUDL + saline in PPTg, 6-OHDA-CPU-DL + BSO - PPTg or saline + saline. The animals of the experiment 1.2 were evaluated between 15 and 44 days after surgery, being euthanized after 45 days. In the second study developed the animals were divided into 5 groups, which were microinjected the CPU-DL right to rotenone (3 mM, 5 mM or 9mm), DMSO (25% - vehicle) or saline, were evaluated between days 15 and 44 post surgical and sacrificed on the 45th day. Were used for behavioral evaluation tests: rotational behavior induced by apomorphine and amphetamine, the grid test, elevated body swing test, drum test, vertical maze and balance in high cross. Twenty-four hours after the behavioral tests the animals were sacrificed and immunohistochemical analysis procedures were performed. For first study, was not detected behavioral change in the 1.1 experiment, however in the 1.2 experiment, there was a reduced performance of the treated groups compared to saline control on the rotarod test. Nevertheless, our results suggest that both 6- OHDA as BSO, when applied to the CPU-DL decrease TH + expression on the CPU-DL and CPU-DM area with increased expression of nNOS protein in the CPU-DL , and the 6-OHDA group also showed an increase in CPU-DM and nucleus accumbens. Still, a scarce increase in the expression of nitrotyrosine protein was observed in the CPU DM and VL on BSO group. The results of 1.2 suggests a possible neuroprotective role of BSO injection in PPTg after neurotoxic effect of 6-OHDA injection the CPU-DL. To the second study, our findings suggest a potential predictive quality of rotenone striatal microinjection as hemiparkinsonismo model because it was able to mimic motor symptoms related to postural balance (rotarod, grid and vertical balance) and immunohistochemical, an increase of nNOS expression and decreased expression of TH+ dose dependent manner in the CPU and the substantia nigra. Our results suggest that neurotoxins, though little exploited when administered intra-striatal pathway, have proved to be potentially effective for inducing changes in the postural balance in experimental models; corroborating therefore a possible interaction of the nigrostriatal dopaminergic system linked to an imbalance nitrergic system, responsible for the oxidative stress/nitrosative related to neurodegeneration. In this sense new studies should be conducted to better understand and elucidate the pathogenesis of PD, as well as new perspectives for future therapeutic strategies.

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21

Sanders, M. "Experiments in rotenoid biosynthesis." Thesis, University of Nottingham, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.376182.

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22

Oster, Sandra. "Untersuchungen zur Dynamik und zum Aggregationsmechanismus von alpha-Synuklein in chronischen Toxinmodellen der dopaminergen Primärzellkultur." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2018. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-232129.

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Ein Schlüsselbefund der Parkinson-Krankheit auf zellulärer Ebene ist das Auftreten von Protein-Einschlusskörperchen, sogenannten Lewykörperchen. Der Hauptbestandteil dieser Lewykörperchen ist pathologisch aggregiertes, fibrilläres α-Synuklein, ein Protein, welches Einfluss auf präsynaptische Vesikel, Protein- und Enzymfunktionen sowie den Dopaminstoffwechsel und den axonalen Transport hat. Bis heute ungeklärt ist die Ursache der Aggregation des Proteins. Zahlreiche Forschungsaktivitäten werden in diese Richtung unternommen. Die pathologischen Mechanismen, die zur abnormen Aggregation von α-Synuklein führen, bleiben noch weitgehend unbekannt. Ein großer Teil der Literatur unterstützt die Hypothese, dass α-Synuklein bei Punktmutationen oder erhöhter Expression anfällig für Aggregationen ist und damit Neuronen geschädigt werden. Die Einzelheiten dieses sukzessiven Aggregationsprozesses und die Mechanismen, die dabei letztlich den Zelltod verursachen, bleiben unklar. Alterungsprozesse und Umweltfaktoren sind entscheidende Risikofaktoren. Obwohl es immer mehr Hinweise gibt, dass α-Synuklein-Aggregate eine wichtige pathophysiologische Rolle spielen, wird bisher noch unzulänglich verstanden, wie die für die dopaminergen Neurone toxische Wirkung entfaltet wird. Als gesicherter Pathomechanismus der Degeneration der dopaminergen Nervenzellen gilt ein erhöhter oxidativer Stress. Es wird vermutet, dass er zur Aggregation des α-Synukleins beitragen kann. Ziel dieser vorgelegten Arbeit ist es, durch die Verwendung eines geeigneten Zellkulturmodells zur Aufklärung der beschriebenen pathologischen Mechanismen beizutragen. In dieser Studie wurden zwei artifizielle Modellsubstanzen in einer dopaminergen Primärzellkultur eingesetzt, die Pestizide Rotenon und Paraquat, um die pathologischen Verhältnisse in der Substantia nigra zu simulieren. Sie erzeugen oxidativen Stress durch Hemmung der mitochondrialen Atmungskette bzw. Redoxreaktionen mit molekularem Sauerstoff, was zum dopaminergen Zelltod führt. Im Rahmen dieser Studie gelang es, beide Parkinson-Zellkulturmodelle anhand der Lokalisierung, des Aggregationsverhaltens, des Einflusses auf die Mikroglia-Aktivierung sowie des Abbaus von α-Synuklein näher zu charakterisieren. Hierzu wurde α-Synuklein durch Fluoreszenzfärbung, Westernblot und Immunpräzipitation analysiert. Eine kurzzeitige Behandlung mit hoch konzentrierten Toxinen löst eine akute Degeneration dopaminerger Neurone aus, die so nicht der des Idiopathischen Parkinsons entspricht. Beim IPS erfolgt die Degeneration über Jahre hinweg. Um auch den Einfluss der zellulären Alterung auf die α-Synuklein-Aggregation zu zeigen, wurden die in dieser Arbeit verwendeten Zellkulturen über 46 Tage kultiviert und die Pestizid-Konzentration so eingestellt, dass etwa 25-50 % der dopaminergen Neurone absterben. Es konnte gezeigt werden, dass es nach chronischer Behandlung mit dem jeweiligen Pestizid zu den verschiedenen Zeitpunkten Unterschiede in der Lokalisation sowie in der Konformation von α-Synuklein gibt. Die zum Vergleich nur bis zum Tag 11 kultivierten Zellkulturen zeigten nach kurzer Behandlung mit hochkonzentrierter Toxin-Menge eine Ansammlung von α-Synuklein im Soma, aber keine Auswanderung und Lokalisierung in und an den Neuriten, wie es nach chronischer Rotenon-Behandlung beobachtet werden konnte. Bei den Rotenon-behandelten Zellen ist ein Prozess der Verlagerung und Anhäufung des α-Synuklein aus dem Soma in die Neuriten bereits ab einem früheren Zeitpunkt zu beobachten als in den Kontrollen, welche sich aber mit zunehmendem Alter ähnlich verhalten. Außerdem konnte in den Kulturen, besonders bei den Rotenon-behandelten dopaminergen Neuronen, ein punktförmiges Verteilungsmuster und größere Ansammlungen des Proteins in den Neuriten beobachtet werden, was für eine aggregierte Form des α-Synukleins spricht. Diese Aggregate ließen sich durch die Proteo-Aggreosom-Färbung nachweisen. Auch der Nachweis von am Serin 129 phosphoryliertem α-Synuklein in diesen größeren Ansammlungen gilt als Zeichen für eine aggregierte Form. Die Beobachtung, dass α-Synuklein mit zunehmendem Kulturalter aus dem Soma in die Peripherie austritt, konnte bei der chronischen Paraquat-Behandlung so nicht getätigt werden. Unter Paraquat-Behandlung war keine Herauf-Regulierung der Gesamt-α-Synuklein Expression in der Kultur zu beobachten, wie dies sowohl bei Kontrolle als auch bei Rotenon der Fall ist. Wir vermuten im Paraquat-Modell, dass die sich im Soma ansammelnde Form von α-Synuklein durch vermehrte Einschleusung in den Zellkern zur Toxizität beitragen kann. Auch eine Interaktion von α-Synuklein mit der Zellmembran könnte unter Paraquat-Einfluss zum dopaminergen Zelltod beitragen. Durch Immunpräzipitation und Fluoreszenz-Doppelfärbung von α-Synuklein und Ubiquitin konnten wir den Abbau des fehlgefalteten α-Synukleins in der Zelle durch Ubiquitinierung nachweisen. Unter Rotenon ist ab DIV 14 eine starke Kolokalisation von α-Synuklein und Ubiquitin zu erkennen, die im Verlauf der Kultur nachlässt und nur noch in punktförmigen Aggregaten außerhalb der Zelle zu sehen ist. Unter Paraquat zeigte sich während der gesamten Kultivierung Polyubiquitinierung und Kolokalisation der beiden Proteine in der gesamten Zelle. Die Aggregationsform von α-Synuklein scheint das Proteinabbausystem durch Ubiquitinierung zu beeinflussen, da wir davon ausgehen, dass es sich bei der α-Synuklein-Konformation zu verschiedenen Zeitpunkten in den Paraquat-behandelten dopaminergen Neuronen nicht um die Aggregationsform handelt, die wir unter Rotenon beobachten konnten.

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Skorupski, Joseph A. Jr. "Effects of CFT Legumine™ Rotenone on Macroinvertebrates in Four Drainages of Montana and New Mexico." Thesis, University of North Texas, 2011. https://digital.library.unt.edu/ark:/67531/metadc84278/.

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Rotenone is considered essential in the restoration of native fish populations; however, the technique is contentious and criticized, specifically concerning impacts to invertebrates. Knowledge of effects to non-target organisms is important for the management and conservation of fish populations. This thesis has two general objectives: (1) demonstrate the influence CFT Legumine™ rotenone has on benthic macroinvertebrates for restoration projects in Montana and New Mexico and (2) evaluate the immediate response by means of invertebrate drift. Chapters 2 and 4 incorporate results from four different restoration projects that examine benthic macroinvertebrate response. Results indicate treatment effects are minimal for Specimen and Cherry Creek projects in Montana. New Mexico projects, Comanche and Costilla Creek suggest a greater influence. Potassium permanganate used to neutralize rotenone, influenced communities in three of the four projects. Regardless, invertebrates in all four projects recovered one-year after treatment. Chapter 3 examines macroinvertebrate drift during rotenone treatment. Results suggest a delayed response compared to previous literature. Rotenone appears to have the greatest immediate influence on the early life stages of Ephemeroptera and Plecoptera. To reduce impacts of rotenone to invertebrates, managers should apply CFT Legumine and use the minimal dosage and duration to complete the projects goal of removing non-indigenous fish species.

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Van, Bruggan N. "Enzyme studies related to rotenoid biosynthesis." Thesis, University of Nottingham, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.381078.

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25

Pretorius, Judey. "Metallothionein expression in tissues of rotenone-treated rats / by Judey Pretorius." Thesis, North-West University, 2006. http://hdl.handle.net/10394/1094.

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Mitochondria1 NADH:ubiquinone oxidoreductase (complex I) carries out a number of well defined functions required for cell physiology. Deficiencies of complex I lead to multi-system disorders that include several well-known phenotypes such as type 2 diabetes mellitus, Alzheimer's disease as well as less known phenotypes such as MELAS, Leigh syndrome and MERRF. It was recently identified that ROS sensitive proteins known as metallothioneins (MTs), are over-expressed in complex I deficient cell lines and that these proteins have a protective effect against ROS related pathologies. It is still not clear if isoform-specific MT expression occurs in this disease and if it plays a significant role in vivo. This study investigated the expression of different MT isoforms in rotenone-treated Sprague Dawley rats, an in vivo model that has been used to study cellular biological responses of mitochondria1 complex I deficiency. The hypothesis of this study states that a rotenone-induced complex I deficiency would lead to an increase of MT mRNA expression in vivo. The specific aim was to determine the relative mRNA expression levels of the three main MT isoforms in rotenone-treated rat tissues. Real-time PCR was used to achieve this aim. In this dissertation the differential expression of MT-1, MT-2 and the brain specific isoform, MT-3 in brain, liver, heart- and skeletal muscle tissues of rotenone-treated Sprague Dawley rats is described. The results indicate that MT-1 expression is significantly increased in the liver as well as, but to a lesser extent, in the brain and heart muscle. MT-1 expression in skeletal muscle was not detected. In contrast, significant increases in expression were observed for MT-2 in all the tissue types with an approximate two-fold increase at the highest rotenone dosage in liver, brain and heart muscle. Skeletal muscle had the smallest increase. For MT-3, no detectable levels of expression could be observed in skeletal and heart muscle. Surprisingly, levels of expression occurred in the liver which slightly (43%), but significantly increased at the highest rotenone dose. As expected, much higher relative levels of MT-3 expression were observed in brain Abstract tissue with a more pronounced increase (almost two-fold) at the highest rotenone dose. As the hypothesis of this study proposed, the in vivo data generated from this study supports the published in vitro data which showed that a rotenone-induced complex I deficiency results in MT expression. This over expression may contribute to a protected effect on the pathology of this disease although this still needs to be established. Furthermore, the results of this study show that the expression of the various MT isoforms in rotenone-treated rat tissues is not expressed in a similar way to the induced deficiency which may point to a differential regulation and response of the three MT isoforms to such a deficiency.
Thesis (M.Sc. (Biochemistry))--North-West University, Potchefstroom Campus, 2006.

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26

Ahmadi, Ferogh Ali. "The mechanism of pesticide rotenone-induced cell death in models of Parkinson's disease /." Connect to full text via ProQuest. IP filtered, 2005.

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Thesis (Ph.D. in Neuroscience) -- University of Colorado at Denver and Health Sciences Center, 2005.
Typescript. Includes bibliographical references (leaves 110-128). Free to UCDHSC affiliates. Online version available via ProQuest Digital Dissertations;

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Takeuchi, Hiroki. "Nicotinic receptor stimulation protects nigral dopaminergic neurons in rotenone-induced Parkinson's disease models." Kyoto University, 2009. http://hdl.handle.net/2433/124255.

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Kadanthode, Rubina John. "An investigation into the neuroprotective effects of melatonin in a model of rotenone-induced neurodegeneration." Thesis, Rhodes University, 2004. http://hdl.handle.net/10962/d1003241.

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Parkinson’s disease, one of the most common neurodegenerative disorders associated with ageing, is characterised by abnormal and profound loss of nigrostriatal dopaminergic neurons. The cause of Parkinson’s disease is unknown, but epidemiological studies suggest an association with pesticides and other environmental toxins, and biochemical studies implicate oxidative damage and mitochondrial impairment, particularly at the level of complex I enzyme. Recently, rotenone, a commonly used organic pesticide and a classical inhibitor of mitochondrial complex I has been reported to reproduce the specific features of Parkinson’s disease in rodents. The mitochondrial respiratory chain is one of the most important sites of reactive oxygen species production under physiological conditions. Toxic free radicals have been implicated in a variety of neurodegenerative diseases as well as ageing itself. Melatonin, a secretory product of the pineal gland is a multifaceted free radical scavenger and natural antioxidant. In the present study, the neuroprotective effects of melatonin against the environmental neurotoxin, rotenone was investigated. Initial studies showed that inhibition of mitochondrial complex I enzyme by rotenone induced superoxide radical generation. Melatonin, administered to the rat in vivo and in vitro was able to offer neuroprotection by curtailing the production of superoxide radicals induced by rotenone. Mitochondria, being the major target of rotenone, the effects of melatonin were investigated at the mitochondrial level. Melatonin was able to increase the electron transport chain activity thus preventing the respiratory inhibition by rotenone. The pineal hormone also counteracted the action of rotenone on complex I enzyme. These results suggest melatonin’s ability to potentially limit the free radical generation and thereby modulate the mitochondrial functions. The detection and measurement of lipid peroxidation is the evidence most frequently cited to support the involvement of free radical reactions in toxicology and in human disease. Melatonin also offered significant protection in vivo and in vitro against rotenone induced lipid peroxidation. Since iron plays a major role in oxidative damage and in the progression of Parkinson’s disease, the effect of melatonin on both rotenone and iron induced lipid peroxidation was investigated, the results of which show that melatonin affords protection and this was suggested to be due to its interaction with the rotenone-iron complex that might have formed. Electrochemical studies were further used to characterise the interactions between melatonin, rotenone and iron (III). Melatonin was shown to bind with iron and thus reducing their toxicity. Histological studies were undertaken to assess the effects of melatonin on rotenone induced toxicity on the dopaminergic neurons in the rat brain. Rotenone treated brains showed extensive neuronal damage whereas with melatonin less damage was observed. Rotenone induces apoptosis via reactive oxygen species production and apoptotic cell death has been identified in PD brains. Furthermore, the apoptotic cell death was detected and quantified by the TUNEL staining. Rotenone treated sections showed signs of apoptosis whereas with melatonin, less apoptotic damage was observed. The findings of this study indicate that the neurohormone, melatonin may protect against rotenone-induced neurodegeneration. Since melatonin production falls substantially during ageing, the loss of this antioxidant is theorized to be instrumental in the degenerative processes associated with advanced age. Considering how devastating diseases such as Parkinson’s disease, are to a patient and the patient’s families, the discovery of protective agents are a matter of urgency. Further investigations using the pesticide model will help to determine the involvement of environmental exposure in the pathogenesis of human diseases as well as to test therapeutic strategies for the treatment of such diseases.

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Pan-Montojo, Francisco, Oleg Anichtchik, Yanina Dening, Lilla Knels, Stefan Pursche, Roland Jung, Sandra Jackson, et al. "Progression of Parkinson's Disease Pathology is Reproduced by Intragastric Administration of Rotenone in Mice." PloS ONE, 2010. https://tud.qucosa.de/id/qucosa%3A29010.

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In patients with Parkinson's disease (PD), the associated pathology follows a characteristic pattern involving inter alia the enteric nervous system (ENS), the dorsal motor nucleus of the vagus (DMV), the intermediolateral nucleus of the spinal cord and the substantia nigra, providing the basis for the neuropathological staging of the disease. Here we report that intragastrically administered rotenone, a commonly used pesticide that inhibits Complex I of the mitochondrial respiratory chain, is able to reproduce PD pathological staging as found in patients. Our results show that low doses of chronically and intragastrically administered rotenone induce alpha-synuclein accumulation in all the above-mentioned nervous system structures of wild-type mice. Moreover, we also observed inflammation and alpha-synuclein phosphorylation in the ENS and DMV. HPLC analysis showed no rotenone levels in the systemic blood or the central nervous system (detection limit [rotenone]<20 nM) and mitochondrial Complex I measurements showed no systemic Complex I inhibition after 1.5 months of treatment. These alterations are sequential, appearing only in synaptically connected nervous structures, treatment time-dependent and accompanied by inflammatory signs and motor dysfunctions. These results strongly suggest that the local effect of pesticides on the ENS might be sufficient to induce PD-like progression and to reproduce the neuroanatomical and neurochemical features of PD staging. It provides new insight into how environmental factors could trigger PD and suggests a transsynaptic mechanism by which PD might spread throughout the central nervous system.

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Lee, Yang. "Structural studies on the monotopic membrane protein, rotenone-insensitive NADH:ubiquinone oxidoreductase from Saccharomyces cerevisiae." Thesis, Imperial College London, 2010. http://hdl.handle.net/10044/1/5658.

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Saccharomyces cerevisiae possesses three mitochondrial NADH:ubiquinone oxidoreductases. The rotenone-insensitive internal NADH:ubiquinone oxidoreductase [Ndi1] is solely responsible for the reduction of ubiquinone by mitochondrial matrix-derived NADH during the process of oxidative phosphorylation. Its homologues from Plasmodium and Mycobacterium bear particular relevance to the treatment of malaria and tuberculosis. It has also been proposed as an agent in gene therapy against mitochondrial complex I dysfunction in disease states such as sporadic Parkinsonism. The work presented in this thesis describes the structural analysis of Ndi1 using x-ray crystallography. The structure of Ndi1 was determined by molecular replacement to 2.5 A resolution. The monomer shares the same fold with the glutathione reductase-structural family. It has a unique C-terminal domain, which contains two amphiphatic helices that lie paralell to the membrane and mediate insertion into the top leaf of the lipid bilayer. The structure depicts a parallel homodimeric biological unit with each protomer presenting a hydrophilic and hydrophobic substrate channel. The dimer arrangement positions the substrate channels in the same orientation relative to the membrane. The flavin ring is positioned at the juncture of the two substrate channels. Only its re-face is accessible to nucleophilic attack. Ndi1 was co-crystallised with NAD+ [2.9 A] and ubiqinone-2 [3.0 A]. Ndi1 quinone-binding and activation is likely to be facilitated by two active-site Thr residues. The ping-pong reaction mechanism of Ndi1 is accounted for by the overlap observed between the pyridine and benzoquinone moieties in the ligand-complexes. This mechanism is similar to quinone reductase NQ01.

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31

Pan-Montojo, Francisco, Oleg Anichtchik, Yanina Dening, Lilla Knels, Stefan Pursche, Roland Jung, Sandra Jackson, et al. "Progression of Parkinson's Disease Pathology is Reproduced by Intragastric Administration of Rotenone in Mice." Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2015. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-185435.

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In patients with Parkinson's disease (PD), the associated pathology follows a characteristic pattern involving inter alia the enteric nervous system (ENS), the dorsal motor nucleus of the vagus (DMV), the intermediolateral nucleus of the spinal cord and the substantia nigra, providing the basis for the neuropathological staging of the disease. Here we report that intragastrically administered rotenone, a commonly used pesticide that inhibits Complex I of the mitochondrial respiratory chain, is able to reproduce PD pathological staging as found in patients. Our results show that low doses of chronically and intragastrically administered rotenone induce alpha-synuclein accumulation in all the above-mentioned nervous system structures of wild-type mice. Moreover, we also observed inflammation and alpha-synuclein phosphorylation in the ENS and DMV. HPLC analysis showed no rotenone levels in the systemic blood or the central nervous system (detection limit [rotenone]<20 nM) and mitochondrial Complex I measurements showed no systemic Complex I inhibition after 1.5 months of treatment. These alterations are sequential, appearing only in synaptically connected nervous structures, treatment time-dependent and accompanied by inflammatory signs and motor dysfunctions. These results strongly suggest that the local effect of pesticides on the ENS might be sufficient to induce PD-like progression and to reproduce the neuroanatomical and neurochemical features of PD staging. It provides new insight into how environmental factors could trigger PD and suggests a transsynaptic mechanism by which PD might spread throughout the central nervous system.

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32

Amos, P. C. "Palladium mediated couplings for the synthesis of rotenoids." Thesis, University of Nottingham, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.235939.

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Ngo, Dung. "Elucidating the Cellular and Molecular Changes of Dopaminergic Neurons by Rotenone-Induced Neurodegeneration in Zebrafish." Thesis, Université d'Ottawa / University of Ottawa, 2018. http://hdl.handle.net/10393/37921.

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Chemical-induced models have revealed the crucial role of oxidative stress and mito-chondrial dysfunction in the development of Parkinson’s Disease. In this project, firstly, we in-vestigated the mechanism of action of rotenone, a commercialized pesticide that was previously described to reproduce the bradykinetic dopaminergic neurodegeneration symptoms of Parkin-son’s Disease in zebrafish by inhibition of the mitochondrial complex I. We found out that rote-none caused change in the morphology of the zebrafish dopaminergic mitochondrial network. We also observed the altered expression of various genes involves in mitochondrial fusion and fission in response to rotenone exposure. Secondly, to develop the use of adult zebrafish as a toxin-based model for Parkinson’s Disease, we sought to minimize any off-target effects by exposure of rotenone specifically to the brain. We demonstrated that microinjection of rotenone into the forebrain ventricular zone of adult zebrafish decreases the number of dopaminergic neurons. However, behavioural tests suggested that did not translate into locomotor impairment in these fish. Taken together, these results gave us more information about the potential use of zebrafish to study the physiological mechanism leading to dopaminergic degeneration and allow for the development of therapeutic strategies for Parkinson’s Disease.

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Seoposengwe, K. M. (Keabetswe Millicent). "The effect of selected medicinal plants on rotenone-induced toxicity in SH-SY5Y neuroblastoma cells." Diss., University of Pretoria, 2013. http://hdl.handle.net/2263/33342.

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Parkinson's disease (PD) is the second most common chronic neurodegenerative disease characterized by dopamine decrease in the substantia nigra. Currently, there is no promising cure for PD and this has resulted in extensive research into alternative medicines. The aim of this study was to investigate the effect of methanol and ethyl acetate extracts of Lannea schweinfurthii (Engl. Engl) (Anacardiaceae), Zanthoxylum capense (Thunb. Harv) (Rutaceae), Scadoxus puniceus ((L.) Friis & Nordal) (Amaryllidaceae) and Crinum bulbispermum (Burm. f.) Milne-Redh. & Schweick) (Amaryllidaceae) on rotenone-induced toxicity in SH-SY5Y neuroblastoma cells. The latter which mimics PD symptoms in vitro. Cytotoxicity of the plant extracts was assessed using sulforhodamine B (SRB) assay. Intracellular reactive oxygen species (ROS) were measured fluorometrically with the use of the fluorescent dye 2‟,7‟-dichlorodihydrofluorescein diacetate (H2DCF-DA). Intracellular glutathione content was measured fluorometrically after staining with monochlorobimane (MCB). Fluorescent dye 5,5‟ ,6,6‟ -tetrachloro-1,1‟ ,3,3‟ -tetraethylbenzimidazolcarbocyanine iodide (JC-1) was used to assess the mitochondrial membrane potential (MMP) status of cells. Apoptosis was assessed by determining caspase-3 activity through detection of 7-amino-4-methylcoumarin (AMC) which is a product of caspace-3 substrate, acetyl-Asp-Glu-Val-Asp 7-amino-4-methylcoumarin (Ac-DEVD-AMC), cleaved by the caspase-3 enzyme. Rotenone was used as an in vitro model to induce PD-like symptoms. Cytotoxicity studies for methanol extract of Zanthoxylum capense revealed the highest IC50 value of 121.3 μg/mL, indicating low toxicity. The ethyl acetate extract of Crinum bulbispermum was observed to have no effect on the normal proliferation of the SH-SY5Y cells and produced an IC50 value >100 μg/mL. The calculated IC50 value obtained from rotenone cytotoxicity studies was 112 iv nM. Zanthoxylum capense and Scadoxus puniceus plant extracts were observed to be neuroprotective against rotenone-induced toxicity. A decrease in intracellular glutathione content as well as MMP was also observed in cells exposed to rotenone alone (50 nM). There was no intracellular ROS generation observed in cells exposed to rotenone alone (50 nM) after 24 h and 72 h. However, apoptotic cell death was observed in cells treated with rotenone (50 nM). Intracellular ROS production was observed to be elevated by methanol and ethyl acetate extracts of C. bulbispermum. Methanol extracts of Z. capense was observed to increase intracellular glutathione content. MMP was increased effectively following treatment with ethyl acetate extract of C. bulbispermum. Moreover, both methanol and ethyl acetate plant extracts were found to decrease caspase-3 activity significantly (p<0.05), in cells exposed to 50 nM rotenone. Z. capense methanol extract reduced caspase-3 activity the most effectively. Treatment with plant extracts was protective and decreased cell death. Furthermore, L. schweinfurthii, Z. capense, S. puniceus and C. bulbispermum, demonstrated strong antioxidant and anti-apoptotic effects against rotenone-toxicity, making them potential agents in developing therapies for treating PD.
Dissertation (MSc)--University of Pretoria, 2013.
gm2014
Pharmacology
unrestricted

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Keow, Jonathan. "Physiological and Behavioral Changes in a Rotenone Model of Dopamine Neurotoxicity and Neurodegeneration in Zebrafish." Thesis, Université d'Ottawa / University of Ottawa, 2016. http://hdl.handle.net/10393/35381.

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Rotenone is a commercially available pesticide with a variety of industrial applications. However, occupational exposure to rotenone has been implicated in the development of Parkinson’s disease. To explore the mechanism of dopamine neuron death secondary to rotenone exposure, the zebrafish was used as a live animal screening tool for environmentally-induced Parkinson’s disease. After testing a variety of small molecule compounds on embryonic zebrafish for their potential to cause dopamine neuron loss, we identified that rotenone exposure induces a bradykinetic dopamine neuron loss phenotype. This phenotype was characterized by decreased locomotion, sensory insensitivity, and a transient but marked decrease in the number of dopamine neurons in embryos exposed to 100nM rotenone, with a concomitant decrease in dopamine transporter mRNA levels. The dopamine neuron deficits were observed in the subpallium, pretectum, olfactory bulb, but these losses were most pronounced in the ventral diencephalon after rotenone exposure. Rotenone damages the mitochondria, generating reactive oxygen species (ROS), and subsequently induces ROS-mediated apoptosis in these dopamine neurons. The rotenone-induced dopamine neuron loss and locomotion phenotypes could be partially rescued in zebrafish larvae with ascorbic acid co-treatment during rotenone exposure. Adults raised from zebrafish embryos exposed to rotenone did not show any deficits to their dopamine neuron distribution, but did show anxiety-like behaviors and upregulation of dopamine receptor D1 mRNA levels. These results suggest that rotenone exposure can cause dopamine neuron death through ROS- mediated apoptosis, and supports an environmental cause of Parkinson’s disease.  La roténone est un pesticide disponible dans le commerce et utilisé pour une variété d’usages industriels. Cependant, l’exposition à la roténone a été impliquée dans le développement de la maladie de Parkinson. Afin d’explorer le mécanisme menant à la perte de neurones dopaminergiques suite à une exposition à la roténone, le poisson-zèbre (Danio rerio) a été utilisée comme modèle animal du développement de la maladie de Parkinson attribuable à des causes environnementales. Après avoir testé une série de petites molécules sur des embryons de poisson-zèbre pour déterminer leur capacité à causer une perte de neurones dopaminergiques, nous avons identifié la roténone comme causant un phénotype de perte de neurones associée à une bradykinésie. Ce phénotype était caractérisé par une perte de la locomotion, une insensibilité sensorielle, et une diminution transitoire mais marquée du nombre de neurones dopaminergiques chez des embryons exposés à une concentration de roténone de 100nM. Ceci coïncidait avec une réduction des niveaux d’expression du gène du transporteur de la dopamine (dat). Des pertes de neurones dopaminergiques furent observés dans le sub-pallium, le pré-tectum et le bulbe olfactif mais étaient plus prononcées dans le diencéphale ventral. La roténone cause des dommages aux mitochondries en générant des dérivés réactifs de l’oxygène (ROS) et, subséquemment, induit une apoptose attribuable aux ROS dans les neurones dopaminergiques. La perte de neurones dopaminergiques due à la roténone ainsi que les déficits locomoteurs ont pu être partiellement empêchés par un co-traitement à l’acide ascorbique. Les poissons adultes ayant été exposés à la roténone au stade embryonnaire ne montrèrent pas de déficits quant à la distribution des neurones dopaminergiques mais présentaient des comportements indiquant un plus haut niveau d’anxiété ainsi qu’une augmentation des ARNm du récepteur D1 de la dopamine. Ces résultats suggèrent que l’exposition à la roténone peut causer la mort des neurones dopaminergiques via une apoptose médiée par les ROS et pourrait constituer une cause environnemental de la maladie de Parkinson.

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36

Farizatto, Karen Lisneiva Garcia. "Estudo da degradação da proteína Tau hiperfosforilada por vias independentes do proteassoma, em modelo experimental de neurodegeneração." Universidade de São Paulo, 2014. http://www.teses.usp.br/teses/disponiveis/5/5160/tde-09122014-133659/.

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O desenvolvimento das doenças neurodegenerativas, como a doença de Alzheimer, está associado à presença de agregados proteicos contendo Tau hiperfosforilada (p-Tau). Esta disfunção da Tau leva a prejuízos na homeostase celular. Um mecanismo chave para diminuir e/ou prevenir os danos promovidos pelos agregados contendo Tau seria o estímulo de sua degradação. Neste sentido, a proposta do presente estudo foi analisar a degradação da proteína Tau após aumento da expressão exógena da cochaperona Bag-2, a qual influencia o sistema proteassomal de degradação; bem como avaliar a ativação dos sistemas de degradação, a fim de correlacionar estes sistemas em cultura de células primárias e organotípica do hipocampo de ratos. Os resultados mostraram que a rotenona foi capaz de aumentar os níveis de p-Tau e que a superexpressão de Bag-2, foi eficiente em prevenir e degradar a p-Tau. O mecanismo envolvido neste processo envolve a coordenação dos sistemas proteassomal e lisossomal, já que a Rab7 e a Rab24 (envolvidas na via lisossomal) mostraram-se diminuídas na fase que antecede a agregação proteica, enquanto houve aumento da Rab24 na presença dos agregados proteicos. Com relação ao peptídeo beta amiloide, foi demonstrado tendência de aumento de p-Tau acompanhado de diminuição da atividade proteassomal e lisossomal. O tratamento com PADK (ativador lisossomal) foi capaz de reverter este efeito nestas diferentes condições. A análise da interrelação entre os sistemas mostrou que uma inibição do proteassoma favorece a via lisossomal e que o inverso não se repete. Os resultados sugerem que a modulação das vias de degradação pode ser interessante para o estudo, prevenção e tratamento das doenças neurodegenerativas associadas à agregação de proteínas
Neurodegenerative diseases, such as Alzheimer\'s, are associated to protein inclusions containing hyperphosphorylated Tau (p-Tau). It is well established that Tau dysfunction impairs cell homeostasis. A key mechanism to prevent and/or reduce the damage promoted by aggregates of Tau might be its degradation. In view of this, the aims of the present study are to evaluate p- Tau clearance following exogenous expression of Bag-2, which stimulates proteasome; as well as to analyze the activation of both lysosome and proteasome pathways in order to understand the crosstalk between these two systems in primary and organotypic cultures of rat hippocampus. Results showed that rotenone was able of increasing p-Tau that was prevented and degraded by Bag-2 overexpression. Mechanisms involved in this process involve the coordination of cell degradation systems, depending upon aggregation status, since Rab7 and Rab24 (involved in lysosomal pathway) were decreased before protein aggregation, while Rab24 increased in the presence of protein inclusions. Amyloid-beta peptide also increased p-Tau accompanied by decreased proteasome and lysosome activity. PADK (lysosomal activator) treatment reverted the inhibition promoted by amyloidbeta peptide. Inhibition of proteasome leads to activation of lysosome, but lysosome inhibition does not affect proteasome. Overall, results suggest that targeting degradation pathways might be useful to understand, prevent and treat neurodegenerative diseases associated with protein deposits

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Sotzny, Franziska. "Regulation des Ubiquitin-Proteasom-Systems unter proteotoxischem Stress." Doctoral thesis, Humboldt-Universität zu Berlin, Lebenswissenschaftliche Fakultät, 2016. http://dx.doi.org/10.18452/17599.

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Das Ubiquitin-Proteasom-System (UPS) stellt eines der wichtigsten zellulären Abbausysteme dar. Es vermittelt die Degradation fehlgefalteter, beschädigter sowie regulatorischer Proteine. Folglich ist es essentiell für die Proteinqualitätskontrolle und für eine Vielzahl zellulärer Prozesse. Eine Störung des UPS steht im engen Zusammenhang mit neurodegenerativen Erkrankungen und malignen Tumoren. Adaptive Mechanismen ermöglichen es der Zelle das UPS an den stetig schwankenden Bedarf proteolytischer Aktivität anzupassen. So wirkt eine erhöhte Expression proteasomaler Gene einem Abfall der proteasomalen Aktivität entgegen. Der Transkriptionsfaktor TCF11/Nrf1 wurde hierbei als Hauptregulator identifiziert. Unter physiologischen Bedingungen ist TCF11/Nrf1 in der ER-Membran lokalisiert und wird über das ER-assoziierte Degradationssystem (ERAD) abgebaut. In Antwort auf Proteasominhibition wird der Transkriptionsfaktor aktiviert und in den Nukleus transferiert. Hier vermittelt er durch Bindung der regulatorischen antioxidative response elements die Genexpression proteasomaler Untereinheiten. Die Ergebnisse dieser Arbeit zeigten, dass es sich bei diesem autoregulatorischen Rückkopplungsmechanismus um einen generellen adaptiven Regulationsmechanismus in Mammalia handelt. Zudem ergaben weitere Untersuchungen, dass der durch Proteasominhibition hervorgerufene oxidative Stress, die TCF11/Nrf1-vermittelte Aktivierung der Genexpression fördert. Die induzierende Wirkung von oxidativem Stress wurde ferner unter Verwendung des Pro-Oxidans Rotenon bekräftigt. Dieses Neurotoxin induziert die TCF11/Nrf1-abhängige Transkription proteasomaler Untereinheiten und folglich die Neubildung aktiver Proteasomkomplexe. Der Transkriptionsfaktor förderte ferner die Zellviabilität Rotenon-behandelter SH-SY5Y Zellen. Diese Ergebnisse demonstrieren, dass die TCF11/Nrf1-vermittelte Genexpression proteasomaler Untereinheiten bedeutend für die Aufrechterhaltung der Redox- sowie der Protein Homöostase ist.
The ubiquitin proteasome system (UPS) represents a major protein degradation machinery. It facilitates the degradation of misfolded and damaged as well as regulatory proteins, thereby ensuring protein quality control and regulation of various cellular processes. Disturbances of the UPS are strongly associated with neurodegeneration and cancer. Adaptive mechanisms enable the cell to deal with changing demand in proteolytic activity. A rise in proteasomal gene expression compensates for decreased proteasomal activity. This adaption is mainly regulated by the transcription factor TCF11/Nrf1. Under unstressed conditions TCF11/Nrf1 resides in the ER-membrane where it is degraded via the ER-associated protein degradation system (ERAD). Proteasome inhibition causes the nuclear translocation of TCF11/Nrf1. In the nucleus, it mediates the gene expression of proteasomal subunits by interacting with their regulatory antioxidant response elements. Within this thesis, it was shown, that this autoregulatory feedback loop represents a general adaptive mechanism in mammalian cells. Moreover, experiments using antioxidative compounds revealed, that the oxidative stress induced by proteasomal inhibition promotes the TCF11/Nrf1-dependent proteasomal gene expression. The inducing effect of oxidative stress was verified using the pro-oxidant rotenone. This neurotoxin activates the transcription of the proteasomal genes resulting in the formation of newly synthesised, active proteasome complexes. Thus, TCF11/Nrf1 exerts a cytoprotective function in response to oxidative and proteotoxic stress in SH-SY5Y cells. In conclusion, this thesis revealed that TCF11/Nrf1-dependent induction of the proteasome expression promotes the maintenance of the redox as well as protein homeostasis.

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Patel, Kishan. "Determination of the hydrogen peroxide concentration in rotenone induced dopaminergic cells using cyclic voltammetry and amplex red." Honors in the Major Thesis, University of Central Florida, 2012. http://digital.library.ucf.edu/cdm/ref/collection/ETH/id/600.

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Parkinson's disease (PD) is a neurodegenerative condition that affects millions of people worldwide. The exact etiology of PD is unknown. However, it is well established that environmental factors contribute to the onset of PD. In particular, chemicals such as the insecticide Rotenone have been shown to increase the death of dopaminergic (DA) neurons by increasing levels of reactive oxygen species (ROS). ROS such as hydrogen peroxide (H2O2) have been shown to be elevated above basal levels in PD patients. Currently, to measure H2O2 concentrations, a commercially available (Amplex® Red) fluorescent assay is used. However, the assay has limitations: it is not completely specific to hydrogen peroxide and can only measure extracellular ROS concentrations. This research focuses on testing an electrochemical sensor that uses cyclic voltammetry to quantitatively determine concentrations of H2O2 released from a cell culture. The sensor was first tested in normal cell culture conditions. Next, chemical interference was reduced and the sensor was optimized for accuracy by altering protein concentrations in the media. Finally, Rotenone was added to a cell culture to induce H2O2 production. Near real-time measurements of H2O2 were taken using the sensor and comparisons made to the fluorescent assay method. Overall, we are trying to determine if the electrochemical sensor can selectively and quantitatively measure H2O2 released from cells. Being able to track the production, migration and concentration of H2O2 in a cell can help researchers better understand its mechanism of action in cell death and oxidative damage, thus getting closer to finding a cure for PD.
B.S.
Bachelors
Burnett School of Biomedical Sciences
Molecular and Microbiology

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39

Martins, Stephanie Alves. "Análise da mobilidade mitocondrial em células vivas do hipocampo, substância negra e locus coeruleus anterior à agregação proteica envolvida em neurodegeneração." Universidade de São Paulo, 2013. http://www.teses.usp.br/teses/disponiveis/5/5160/tde-07022014-103631/.

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A alteração do tráfego mitocondrial em neurônios leva ao aumento do estresse oxidativo, privação de energia, deficiência da comunicação intercelular e neurodegeneração. Há evidências de que essas alterações de tráfego antecedem a morte neuronal associada à agregação proteica. Portanto, conhecer a relação entre a mobilidade mitocondrial e a formação de agregados proteicos pode ser um passo importante para o melhor entendimento dos mecanismos da neurodegeneração. Com isso, o objetivo do presente estudo é analisar a mobilidade das mitocôndrias em culturas de células do hipocampo, substância negra e locus coeruleus expostas a rotenona e MPTP, como agentes neurodegenerativos, e à rapamicina como ativador da autofagia. Um outro objetivo do estudo é avaliar o papel do cálcio (através do emprego de EGTA e ionomicina) no modelo experimental. Os resultados mostraram aumento da mobilidade mitocondrial no hipocampo e diminuição na substância negra, já no locus coeruleus houve aumento seguido de diminuição da mobilidade mitocondrial dependendo da concentração de rotenona. O emprego do EGTA e ionomicina mostra que a ação da rotenona sobre o tráfego mitocondrial envolve o cálcio, mas não se relaciona com uma possível alteração da integridade mitocondrial, já que não foi observada alteração no potencial de membrana mitocondrial. Foram também realizados experimentos a fim de avaliar a mobilidade mitocondrial em modelo utilizando rapamicina para ativar a autofagia e MPTP como indutor da neurodegeneração em culturas de células, onde foi observado aumento da mobilidade no hipocampo e no locus coeruleus quando exposto a rapamicina e aumento da mobilidade mitocondrial em cultura de células do hipocampo exposto a MPTP já no locus coeruleus houve uma diminuição significativa da mobilidade mitocondrial. Os resultados permitem concluir que o tráfego mitocondrial está alterado antes da agregação proteica podendo contribuir com a neurodegeneração
Altered mitochondrial traffic in neurons can lead to increased oxidative stress, energy deprivation, impaired intercellular communication and neurodegeneration. There are evidences mitochondria disturbing precedes neuronal death associated with protein aggregation. Therefore, the study of mitochondrial traffic and protein aggregation can be an important step towards a better understanding of the mechanisms of neurodegeneration. Thus, the aim of this study is to analyze mitochondria mobility in cultured cells of the hippocampus, substantia nigra and locus coeruleus exposed to rotenone and MPTP, as neurodegeneration-promoting agents, and rapamycin to activate autophagy. The other objective of the study was to analyze the role of calcium (through EGTA and ionomycin) in the experimental model. The results showed increased and decreased mobility mitochondrial in cells from hippocampus and substantia nigra, respectively, while the locus coeruleus cell culture has increased followed by decreased mitochondrial mobility depending upon rotenone concentration. The use of EGTA and ionomycin showed that alteration of mitochondrial traffic is associated with calcium, however it is not related with changes in mitochondrial membrane potential. Additional experiments were also conducted to assess mitochondrial mobility in a model using rapamycin to activate autophagy and MPTP to induce neurodegeneration in cell cultures. The results of these experiments showed increased mitochondrial mobility in the hippocampus and locus coeruleus when exposed to rapamycin; while MPTP also increased mitochondria mobility in hippocampal cell cultures, but decreased it in locus coeruleus. Results suggest that mitochondrial traffic is altered before protein aggregation, which may contribute to neurodegeneration

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40

Alessandrini, Marco. "Evaluation of the effects of coenzyme Q10 and succinate in a rotenone-induced complex I deficient rat model / by Marco Alessandrini." Thesis, North-West University, 2006. http://hdl.handle.net/10394/491.

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Disorders of the mitochondrial respiratory chain have an incidence ranging from 1 in 2,000 to 1 in 5,000, with the most frequent of these cytopathies resulting from causative alterations within mitochondrial complex I, the first enzyme of the respiratory chain. The biochemical consequences of a complex I deficiency include, amongst others, failure to oxidise reduced nicotinamide adenine dinucleotide (NADH), impairment of the Krebs cycle, elevated blood lactate, lowered adenosine triphosphate (ATP) generation and an increased production of reactive oxygen species (ROS). The aim of the investigation was to evaluate the effects of CoQ10 and succinate in a rotenone-induced animal model. Sprague Dawley rats were dosed with rotenone for a period of 14 days via oesophageal intubation, resulting in the successful establishment of a complex I deficient animal model. Upon optimisation of the rotenone concentration, rat diets were supplemented with high concentrations of either coenzyme Q10 or succinate for two days in an attempt to alleviate the biochemical manifestations of the rotenone induced complex I deficiency. Five tissue types were collected and assayed for a total of seven biochemical parameters, which enabled the establishment of a biochemical profile of response for each of the tissue groups. Data generated from the study revealed that rotenone, when dosed in high concentrations, contributed to the alleviation of serum hydro peroxide levels. This result was confirmed by the unexpected finding that rotenone itself harboured an antioxidant capacity equivalent to that of Trolox, the vitamin E analogue generally used for the determination of antioxidant capacity. It was therefore concluded that rotenone was not an ideal inhibitor for the evaluation of complex I deficiency and ROS-related investigations in an animal model. Since this compound is the most widely used inhibitor of complex I, the data from the study affirms the use of alternative complex l inhibition strategies. Finally, the data was suggestive of the fact that both coenzyme Q10 and succinate exclusively improved isolated components of the biochemical profile. Results generated in this study thus support current therapeutic intervention where patients receive a combination of vitamins and cofactors as part of a management strategy for the mitochondrial cytopathies.
Thesis (Ph.D. (Biochemistry))--North-West University, Potchefstroom Campus, 2007.

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41

Scholz, Christian. "The role of K ATP channels in model systems of dopaminergic neuron loss in the ventral mesencephalon." [S.l. : s.n.], 2008. http://nbn-resolving.de/urn:nbn:de:bsz:16-opus-80809.

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42

Guzzo, Élio César. "Seleção de genótipos de feijoeiro Phaseolus vulgaris (L.) (Leguminosae) resistentes aos carunchos Acanthoscelides obtectus (Boh.) e Zabrotes subfasciatus (Say) (Coleoptera: Bruchidae) e o seu uso associado com inseticidas botânicos." Universidade de São Paulo, 2008. http://www.teses.usp.br/teses/disponiveis/11/11146/tde-16072008-131053/.

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Este estudo foi realizado com o objetivo de identificar genótipos de feijão Phaseolus vulgaris resistentes aos carunchos Acanthoscelides obtectus e Zabrotes subfasciatus, bem como avaliar o efeito associado desses genótipos resistentes com inseticidas de origem vegetal. Para tanto, foram utilizados acessos de P. vulgaris do Banco de Germoplasma do Instituto Agronômico de Campinas e inseticidas comerciais de origem botânica. No screening inicial, amostras dos genótipos foram infestadas com cada uma das espécies de bruquídeos separadamente, avaliando-se o número de insetos emergidos aos 50 dias após a infestação. Dos 49 genótipos testados contra A. obtecus, não houve emergência naqueles com números de acesso 525, 584 e 615, podendo ser considerados os mais resistentes. Em relação a Z. subfasciatus, os genótipos com números de acesso 2, 35, 251, 570, 583, 584, 610, 621, 634, 816, 818 e 819 se mostraram mais resistentes entre os 185 avaliados. Destes, os genótipos portadores de arcelina 583, 584, 816, 818 e 819, além de 570 e 610, foram selecionados como os mais promissores para os testes subseqüentes, juntamente com a variedade Bolinha, que foi utilizada como controle de suscetibilidade. Não foi observada correlação entre as características morfoagronômicas dos genótipos de P. vulgaris e a sua resistência às espécies de bruquídeos avaliadas, indicando que a resistência a estas pragas não está associada às características da flor, vagem, semente e fenologia dos genótipos. A massa de mil sementes, que é indicativa da origem dos genótipos, foi um dos descritores analisados, mostrando também que a resistência de P. vulgaris a A. obtectus e a Z. subfasciatus não está relacionada à origem dos genótipos. Em testes de livre escolha e de confinamento, avaliou-se o efeito dos genótipos selecionados no screening, juntamente com a variedade Bolinha, sobre o comportamento e biologia de Z. subfasciatus. Verificou-se que a avaliação da preferência de Z. subfasciatus por genótipos de P. vulgaris em teste de livre escolha pode ser feita com 1 dia após a infestação e que \'Bolinha\', apesar de ser suscetível a Z. subfasciatus e favorecer o seu desenvolvimento, apresenta antixenose para oviposição em relação à praga. Nos testes realizados, os genótipos contendo arcelina tenderam a ser mais resistentes que os demais sem essa proteína, sendo que os seus efeitos sobre Z. subfasciatus incluíram o aumento da mortalidade no período de desenvolvimento, alongamento desse período e redução do peso de adultos emergidos, mantendo-se, de certa forma, estáveis ao longo de duas gerações da praga. A resistência conferida pela arcelina revelou ser do tipo antibiose, tendo como causas a impropriedade nutricional e a ação no metabolismo do inseto. Com relação aos inseticidas botânicos, foram testados 3 produtos comerciais, sendo 2 à base de azadiractina e um à base de rotenona. Entre estes, o produto que mais afetou o desenvolvimento de Z. subfasciatus foi NeemPro®, derivado de nim (Azadirachta indica), o qual apresentou efeito ovicida e prolongou a duração do período de desenvolvimento de Z. subfasciatus. Frente a isto, avaliou-se o efeito associado de NeemPro® com o genótipo resistente portador de arcelina 818 sobre alguns parâmetros biológicos de Z. subfasciatus. Verificou-se que os efeitos mais severos sobre Z. subfasciatus foram causados pelo genótipo resistente, independentemente do inseticida à base de nim e que o uso associado de ambos não provoca efeito aditivo ou sinérgico, não sendo recomendado para o manejo de Z. subfasciatus.
This research was carried out to identify Phaseolus vulgaris genotypes resistant to the bean weevils Acanthoscelides obtectus and Zabrotes subfasciatus, as well as to evaluate the effect of these genotypes in association with botanical insecticides. To reach this objective, P. vulgaris accessions from the Germplasm Bank of Instituto Agronômico de Campinas and commercial insecticides from botanical origin were tested. In the initial screening, samples of bean genotypes were infested with the weevil species separately and the number of adults emerged at the 50th day after infestation was evaluated. There was no A. obtectus emergence in genotypes 525, 584 and 615, among the 49 ones screened against this pest. In relation to Z. subfasciatus, genotypes with accession numbers 2, 35, 251, 570, 583, 584, 610, 621, 634, 816, 818 and 819 showed themselves resistant among 185 screened ones. The arcelin-containing genotypes 583, 584, 816, 818 and 819, plus 570 and 610 (both lacking this protein), were selected as the most promising for additional evaluations. Bolinha variety was also used as the susceptible standard. No correlation between morpho-agronomical characteristics of the P. vulgaris genotypes and their resistance to the weevils was observed, indicating that resistance to these two pests is not associated to genotypes flower, pod and seed characters or plant phenology. The mass of 1000 seeds, which indicates the origin of genotypes, was one of the used descriptors, showing that P. vulgaris resistance to A. obtectus and Z. subfasciatus is not related to genotypes origin too. In free- and no-choice tests, it was evaluated the effect of the screened genotypes on Z. subfasciatus behavior and biology, compared to \'Bolinha\'. It was verified that in free-choice tests, the evaluation of Z. subfasciatus preference for P. vulgaris genotypes can be done 1 day after infestation. Despite being susceptible to Z. subfasciatus and supporting its development, \'Bolinha\' holds antixenosis for oviposition in relation to the pest. In the bioassays carried out, genotypes containing arcelin tended to be more resistant than those lacking this protein and their effects on Z. subfasciatus include increasing of the mortality in the developmental period, enlargement of this period and reduction in adult weight, also being stable during two pest generations. The resistance provided by arcelin revealed itself to be antibiosis, by acting as antinutrients and also as antimetabolics. In relation to botanical insecticides, 3 commercial products, 2 of them based on azadirachtin and 1 based on rotenone, were evaluated. The insecticide NeemPro®, extracted from neem (Azadirachta indica) was the only one significantly causing ovicidal effect and enlarging Z. subfasciatus developmental period. Based on these results, the associated effect of NeemPro® and the resistant arcelin-containing P. vulgaris genotype 818 on some Z. subfasciatus biological parameters was evaluated. It was verified that the most severe effects on Z. subfasciatus were caused by the resistant bean genotype, independently of the neem based insecticide. The associated use of these two control methods no results in additive or synergistc effect and is not recommended for the management of Z. subfasciatus.

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Meeding, Lizette. "Metabolic markers to distinguish between moniliformin and 3-bromopyruvate induced pyruvate dehydrogenase and rotenone-induced respiratory chain complex I deficiencies in HeLa cells / Lizette Meeding." Thesis, North-West University, 2009. http://hdl.handle.net/10394/4974.

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Deficiencies of the pyruvate dehydrogenase complex enzyme and of the mitochondrial respiratory chain enzymes in humans both result in similar metabolic profiles in blood and urine. It is therefore almost impossible to distinguish between the two conditions based on the metabolic profile alone. Definitive diagnosis can only be made by assessing enzyme function in muscle biopsies. The aim of this study was to attempt to identify a method that is easy, non-invasive and definitive to distinguish between deficiencies in the two enzyme complexes. HeLa cells were treated with moniliformin and 3-bromopyruvate (inhibitors of pyruvate dehydrogenase) and rotenone (inhibitor of complex I) to induce pyruvate dehydrogenase complex and mitochondrial respiratory chain deficiencies respectively. After inhibition for 24 hours, the media were transferred to a clean tube and centrifuged. The cells were scraped off, sonified and centrifuged. Organic acid analyses were done on the media and cell extracts using gas chromatography-mass spectrometry. Identification of the organic acids in the chromatogram was done by using AMDIS software and a library compiled by Prof L.J. Mienie at the metabolic laboratory of the North-West University, Potchefstroom. I tested several hypotheses in order to achieve the aim of this study. The measured organic acid levels varied markedly which made it difficult to interpret. Organic acid comparisons of cell extracts were not significantly different, and were therefore not discussed. Not enough data was obtained to calculate the ratio limits of 4-hydroxyphenylpyruvic acid, 4-hydroxyphenyllactic acid and 4-hydroxyphenylacetic acid. This approach was therefore rejected. The calculation of the ratio limit of phenylpyruvic acid, phenyllactic acid and phenylacetic acid could also not be done because these molecules could not be detected in the medium. This approach was also rejected. No discernable pattern was observed in the principle component analysis (PCA). Our results therefore make it doubtful that PCA can be used as a tool to diagnose and distinguish between deficiencies in the pyruvate dehydrogenase complex enzymes and mitochondrial respiratory chain enzymes. With inhibition of pyruvate dehydrogenase, the ratios of citric acid to succinic acid and citric acid to fumaric acid were significantly decreased and fumaric acid to malic was significantly increased. Respiratory chain inhibition with rotenone had no marked effect on these three ratios. It is therefore likely that calculation of these ratios may distinguish between pyruvate dehydrogenase defect and a respiratory chain defect. This will have to be verified in patients with proven enzyme defects.
Thesis (M.Sc. (Biochemistry))--North-West University, Potchefstroom Campus, 2010.

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44

Lira, Arman. "The Immune Response in Parkinson's Disease." Thèse, Université d'Ottawa / University of Ottawa, 2014. http://hdl.handle.net/10393/30515.

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Microglia activity has been detected in Parkinson’s disease (PD) post-mortem brains and experimental animal models; however the precise interplay between microglia and dopamine neurons of the SNpc is not well understood. In the blood plasma of PD patients, our laboratory found elevated levels of interferon-gamma (IFN-γ), a proinflammatory cytokine and potent activator of microglia. Given this, we sought to untangle the immune responses relevant to PD in mice, examining IFN-γ’s involvement and signaling mechanism using an inflammatory co-culture model of microglia and midbrain neurons treated with rotenone. By means of RT-PCR, we discovered IFN-γ mRNA transcripts are produced by microglia, and this expression increases upon exposure to rotenone. We delineated IFN-γ’s signaling mechanism in co-cultures using different IFN-γ receptor deficient cells, and showed it engages receptors in an autocrine (not paracrine) manner to further microgliosis and dopamine cell loss. After exploring the innate immune response in a model of PD, we subsequently shifted focus to an in vivo system to better investigate any involvement of the delayed humoral arm of the adaptive immune system. Needing a time appropriate death paradigm, we developed a protracted low dose regimen of MPTP, which elicits dopaminergic cell death after 2 weeks of treatment. Subjected to this paradigm, Rag 2 mutant mice (deficient in both T and B cells) exhibit resistance to dopamine cell loss, microglia activation and motor impairments. Further evidence in support of immune involvement came with the resensitization of Rag2 mice to MPTP after reconstitution with WT splenocytes. Additionally, mice deficient in Fcγ receptors exhibited neuroprotection in our protracted degeneration model. Taken together, these data indicate the innate and humoral arm can modulate the microglial response to dopaminergic degeneration and may participate in Parkinson's disease.

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45

Telkes, Ilknur. "Phase Validation Of Neurotoxic Animal Models Of Parkinson." Master's thesis, METU, 2012. http://etd.lib.metu.edu.tr/upload/12614866/index.pdf.

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Parkinson&rsquo
s disease (PD) is characterized by the progressive loss of dopaminergic nigral neurons and striatal dopamine resulting in serious motor deficits but also some non-motor anomalies. Animal models of human neurodegenerative diseases are essential for better understanding their pathogenesis and developing efficient therapeutic tools. There are many different PD models, however, none of them is fully reproducing all the symptoms of the disease. In addition, different investigators use different behavioral measures which makes even more difficult to compare and evaluate the results. The aim of the present study was to compare motor and cognitive deficits in two most common models of PD: the Rotenone and 6-OHDA model, using a large battery of neurological tests and a probabilistic learning task. To the best of our knowledge, this is the first study to examine the effects of bilaterally induced Rotenone and 6-OHDA through behavioral test batteries assessing the cardinal motor symptoms and the cognitive abnormality of Parkinson&rsquo
s Disease in the same rat population. Also, the present study is unique on the basis of providing both longitudinal observations of behaviour in the same treatment group and the cross-sectional comparisons of the behavioural responses between different groups. In the current study, the neurotoxins were applied at relatively low doses of 3-4 &mu
g, bilaterally to the substantia nigra pars compacta (SNpc). Experiments were conducted on 50 young-adult male Sprague&ndash
Dawley rats randomly assigned to five experimental groups: Rotenone, 6-OHDA, vehicle (DMSO/Saline), and the intact control. The neurological tests included locomotor activity,catalepsy, rearing, stepping, and rotarod/accelerod tests. They were applied prior to, and on days 4-7-10-20-40-150 while the learning task was applied 49 days after drug infusion.During the first 2 postoperational months, both neurotoxins produced progressive deterioration in motor performance but showing no effect on cognitive functions. Five months after the surgery, regression of bradykinesia but persistence of sensorimotor deficits was noted. The tests&rsquo
results suggest different susceptibility of different motor functions to the degeneration of nigro-striatal (N-S) pathway. So, different tests were demonstrated to have different power in detecting similar motor deficits.

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46

Wilson, Lois Kathryn. "A probe of the rotenone-piericidin a-amytal binding site of NADH-coenzyme Q reductbase by structure-activity relationships between the new natural benzofuran inhibitor hydroxytremetone and related ben." Thesis, Georgia Institute of Technology, 1989. http://hdl.handle.net/1853/26005.

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47

Rotenhan, Juliane von Verfasser], Anja [Gutachter] [Amend-Traut, and Steffen [Gutachter] Schlinker. "Frankfurter Testamentsstreitigkeiten am Reichskammergericht: Eine Untersuchung anhand der Gerichtsakten der höchstrichterlichen Spruchpraxis (1495-1806) / Juliane von Rotenhan. Gutachter: Anja Amend-Traut ; Steffen Schlinker." Würzburg : Universität Würzburg, 2015. http://d-nb.info/1111887233/34.

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48

Stiévenard, Aliçia. "Investigation of the roles of ghrelin in experimental models of early stages of Parkinson’s disease : towards a clarification of ghrelin’s diagnostic and therapeutic potentials." Thesis, Lille 2, 2016. http://www.theses.fr/2016LIL2S041/document.

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La maladie de Parkinson (MP) est une maladie neurodégénérative caractérisée par trois symptômes moteurs principaux : la bradykinésie, la rigidité et le tremblement de repos. Son diagnostic définitif repose sur l’identification post-mortem d’une importante mort des neurones dopaminergiques de la substance noire (SN) et la présence de corps de Lewy dans les neurones survivants. Cette maladie progresse lentement et les premiers symptômes moteurs n’apparaissent qu’après la dégénérescence de plus de 50% de la SN. Le diagnostic clinique de MP est donc établi tardivement, réduisant ainsi la fenêtre d’action thérapeutique. De plus, les traitements actuels ne soulagent que temporairement les symptômes moteurs. Les défis de la recherche actuelle pour la MP sont donc : 1) d’anticiper le diagnostic de la MP à un stade où la SN est encore suffisamment intacte pour mettre en place des stratégies neuroprotectrices, et 2) d’améliorer les traitements actuels et/ou développer de nouvelles stratégies thérapeutiques pour stopper la progression de la maladie avant que le phénotype moteur ne soit installé. Le stade clinique de la MP est précédé d’une phase prémotrice durant laquelle les patients présentent souvent des symptômes non moteurs tels que l’anosmie, la dépression ou la constipation. Des travaux récents suggèrent que les lésions caractéristiques de la MP pourraient d’abord apparaître dans le système nerveux périphérique puis progresser lentement jusqu’au cerveau. Ces stades précoces de la MP sont cependant mal connus et leurs caractéristiques méritent d’être étudiées dans des modèles expérimentaux appropriés. Ainsi, des études récentes ont montré que la ghréline, un peptide gastro-intestinal, protège les neurones dopaminergiques de la SN contre la mort dans des modèles in vivo et in vitro de syndrome parkinsonien. De plus, dans un modèle animal de syndrome parkinsonien, la ghréline prévient l’aggravation des symptômes gastro intestinaux par la L-DOPA, traitement médicamenteux principal de la MP. Enfin, des altérations des concentrations plasmatiques de ghréline ont également été observées chez les patients aux stades précoces de la maladie. Dans ce contexte, nous avons émis l’hypothèse que la ghréline pourrait jouer un rôle important aux stades précoces de la maladie et donc être utilisée comme biomarqueur et/ou agent neuroprotecteur dans la MP. Ainsi, l’objectif de ma thèse était d’étudier les rôles de la ghréline aux stades précoces de la MP par des approches in vitro et in vivo.La première étape a consisté à déterminer les effets de la ghréline dans des cultures primaires de cellules mésencéphaliques exposées au pesticide roténone, un inhibiteur du complexe I mitochondrial connu pour son association avec la MP. Contrairement aux données de la littérature, nous montrons un effet délétère en fonction de la dose et du temps sur les cellules exposées à la roténone. Nous ne confirmons donc pas l’effet neuroprotecteur de la ghréline dans nos conditions expérimentales. En parallèle, nous avons étudié le potentiel de la ghréline en tant que biomarqueur dans un modèle murin de syndrome parkinsonien reproduisant les stades précoces de la maladie après exposition orale chronique à de faibles doses de roténone. Nous avons d’abord validé ce modèle et confirmé le développement des altérations non motrices et l’absence de mort neuronale au sein de la SN après 1.5 mois de ce régime. En revanche, nos résultats ne montrent pas de modification des taux plasmatiques de ghréline chez les souris exposées 1.5 mois à la roténone. Cependant, des facteurs tels que l’anxiété pourraient avoir affecté les taux de ghréline. Ces données devront donc être confirmées avec des animaux stratifiés selon leur niveau d’anxiété et/ou de plus longues expositions. En conclusion, nos résultats interrogent le rôle neuroprotecteur de la ghréline dans la MP et posent les bases pour de futures recherches sur l’implication de cette hormone orexigène dans la MP
Parkinson’s disease (PD) is the second most frequent neurodegenerative disease in the world. It is characterized by motor symptoms such as bradykinesia, rigidity and resting tremor. Its definite diagnosis relies on the identification of specific neuropathological hallmarks at autopsy including severe neuronal death within the substantia nigra (SN) and the presence of Lewy bodies in the surviving neurons. PD progresses slowly and the first motor symptoms appear when more than 50% of the SN has degenerated. Therefore, the clinical diagnosis is established late in the course of the disease, thus restricting the therapeutic window for clinicians. In addition, the currently available therapeutic options can only temporarily alleviate PD motor symptoms. The challenges of current PD research are: 1) to anticipate the diagnosis and be able to identify the disease as early as possible, when the SN is still intact enough to implement a disease-modifying/neuroprotection strategy to prevent the appearance of motor symptoms, and 2) to improve current medications and/or develop new therapeutic strategies able to stop the disease before the motor phenotype is installed. The decade preceding PD clinical diagnosis is of particular interest since patients often complain about non-motor symptoms such as anosmia, depression or constipation. Moreover, recent evidences suggest that PD-characteristic lesions could first appear in the peripheral nervous system and slowly progress towards the brain. Thus PD earlier stages and their characteristics deserve better investigations using appropriate experimental models. In this regard, recent studies realized in animal and cellular models of advanced parkinsonism have suggested that ghrelin, an orexigenic peptide mainly produced in the stomach, could play a neuroprotective role in PD. Indeed, exposure to ghrelin has shown a protective effect against the neuronal death in animal and cellular models of parkinsonism. In addition, in a rodent model of parkinsonism, ghrelin was shown to alleviate the L-DOPA-induced worsening of gastro-intestinal symptoms, L-DOPA being the current main therapeutic option in PD. Moreover, ghrelin plasma concentrations have shown alterations in early stages of the disease in small cohorts of PD patients. We therefore hypothesized that ghrelin might play an important role in PD early stages and could serve as a biomarker and a neuroprotective agent in PD. In this context, the aim of my PhD was to investigate the roles of ghrelin in PD early stages using both in vitro and in vivo approaches.We first studied the effects of ghrelin in primary mesencephalic cells exposed to the pesticide rotenone, a potent inhibitor of mitochondrial complex I known for its association with PD. Contrary to the data of the literature, we show a dose and time-dependant deleterious effect of ghrelin on mesencephalic cells exposed to rotenone. This does not confirm the neuroprotective potential of ghrelin in our experimental conditions. In parallel, we investigated the potential of ghrelin as a biomarker in a rodent model of parkinsonism mimicking early stages of the disease after chronic oral exposure to low doses of rotenone. We first validated this model in our animal facility and confirmed that mice exposed to such a regimen develop progressive non-motor alterations but no dopaminergic neuronal death in the SN after 1.5 months. Our initial results do not show a modification of plasma ghrelin levels in rotenone-exposed mice at early stages of the pathological condition. However, confounding factors such as anxiety might have altered ghrelin levels. This should therefore be further ascertained in animals stratified for their anxiety levels and/or in longer exposures. In conclusion, these results challenge the suggested role of ghrelin as a disease-modifying agent in PD and set the bases for future investigations of ghrelin in the context of PD

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49

Stuckey, Crystal Elaine. "Oxidative Stress and Cell Death in Osmotically Swollen Glial Cells." Wright State University / OhioLINK, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=wright1208492663.

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50

Pretorius, Marianne. "Evaluation of metallothionein involvement in the modulation of mitochondrial respiration in mice / Marianne Pretorius." Thesis, North-West University, 2011. http://hdl.handle.net/10394/9195.

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Metallothioneins (MTs) are small, non-enzymatic proteins that are involved in cellular detoxification and metal homeostasis because of their high cysteine content. MTs have also been identified as one of the vast number of adaptive responses to mitochondrial respiratory chain (RC) deficiencies. Aside from this, numerous other studies have linked MTs to several mitochondrion-linked components, including reactive oxygen species (ROS) and oxidative stress, apoptosis, glutathione, energy metabolism and nuclear- and mitochondrial DNA transcription regulation. However, most of the reports concerning the putative link between MTs and mitochondria are from in vitro studies and relatively little supportive in vivo evidence has been reported. Information on the involvement of MTs with respiratory chain function is especially limited. Is was therefore the aim of this study to investigate the involvement of MTs in mitochondrial respiration and respiratory chain enzyme function by using an MT knockout (MTKO) mouse model, which was treated with the irreversible complex I inhibiting reagent, rotenone. The aim was achieved by implementing three objectives: firstly, the RC function was investigated as a complete working unit; secondly, the functional and structural properties of single units (enzymes) of the RC were investigated utilising enzyme activity assays and BN- PAGE/western blot analysis; and thirdly, the possible effect of MTs on mtDNA copy number was investigated. While some tendencies of variation in RC enzyme activity and expression were identified, no significant effect on the overall mitochondrial respiratory function, or any significant differences in the relative mtDNA copy number of MTKO mice were observed. Thus it is concluded, while MTs have in this study revealed relatively small changes in respiratory chain function, which may still prove to have biological ignificance in vivo, the exact nature of the putative role of MTs in mitochondrial respiration or oxidative phosphorylation remains undefined.
Thesis (MSc (Biochemistry))--North-West University, Potchefstroom Campus, 2012.

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Dissertations / Theses on the topic 'Rotenona'

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